Delivery system and method for self-centering a proximal end of a stent graft

ABSTRACT

A method for implanting a prosthesis centrally within a curved lumen includes loading a prosthesis into a delivery sheath, advancing the sheath in a patient towards the curved lumen to place at least the proximal end of the prosthesis within the curved lumen, and centering the proximal end of the prosthesis and/or the distal end of the sheath within the curved lumen. In a first advancing step, the outer catheter containing the inner sheath is advanced together towards the curved lumen to a location proximal of the curved lumen and, in a second advancing step, the inner sheath containing the prosthesis is advanced into the curved lumen to place at least the proximal end within the curved lumen while the outer catheter substantially remains at the location. After centering, the proximal end of the prosthesis is deployed centered within the curved lumen.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.15/839,272, filed on Dec. 12, 2017, now U.S. Pat. No. 10,646,365, issuedon May 12, 2020, which is a continuation of U.S. patent application Ser.No. 14/575,673, filed Dec. 18, 2014, now abandoned, which is acontinuation of U.S. patent application Ser. No. 13/024,882, filed Feb.10, 2011, now abandoned, which is a continuation of U.S. patentapplication Ser. No. 11/701,876, filed Feb. 1, 2007, now abandoned,which claims the benefit under 35 U.S.C. § 119(e) of U.S. ProvisionalApplication Nos. 60/851,282, filed Oct. 12, 2006, 60/833,533, filed Jul.26, 2006, and 60/765,449, filed Feb. 3, 2006. U.S. application Ser. No.11/701,876 is also a continuation-in-part of U.S. patent applicationSer. No. 10/884,136, filed Jul. 2, 2004, now U.S. Pat. No. 7,763,063,which claims the benefit under 35 U.S.C. § 119(e) of U.S. ProvisionalApplications Nos. 60/500,155, filed Sep. 4, 2003, and 60/499,652, filedSep. 3, 2003; and is also a continuation-in-part of U.S. patentapplication Ser. No. 10/784,462, filed Feb. 23, 2004, now U.S. Pat. No.8,292,943, which also claims the benefit under 35 U.S.C. § 119(e) ofU.S. Provisional Applications Nos. 60/500,155, filed Sep. 4, 2003, and60/499,652, filed Sep. 3, 2003, and said Ser. No. 10/884,136, filed onJul. 2, 2004, now U.S. Pat. No. 7,763,063 is a Continuation-in-Part ofSer. No. 10/784,462, filed Feb. 23, 2004, which claims benefit under 35U.S.C. § 119(e) U.S. Provisional Application Nos. 60/500,155, filed Sep.4, 2003, and 60/499,652, filed Sep. 3, 2003. The entire teachings of theabove applications are incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

n/a

BACKGROUND OF THE INVENTION Field of the Invention

The invention lies in the field of endoluminal blood vessel repairs. Theinvention specifically relates to a delivery system and method forself-centering a proximal end of a stent graft, for example, forendoluminally repairing aneurysm and/or dissections of the thoracictransverse aortic arch, thoracic posterior aortic arch, and thedescending thoracic portion of the aorta. The present invention lies inthe field of prosthesis delivery systems, in particular, to a stentcapture device for releasably holding a stent graft in an endovascularstent graft delivery system.

Description of the Related Art

A stent graft is an implantable device made of a tube-shaped surgicalgraft covering and an expanding or self-expanding frame. The stent graftis placed inside a blood vessel to bridge, for example, an aneurismal,dissected, or other diseased segment of the blood vessel, and, thereby,exclude the hemodynamic pressures of blood flow from the diseasedsegment of the blood vessel.

In selected patients, a stent graft advantageously eliminates the needto perform open thoracic or abdominal surgical procedures to treatdiseases of the aorta and eliminates the need for total aorticreconstruction. Thus, the patient has less trauma and experiences adecrease in hospitalization and recovery times. The time needed toinsert a stent graft is substantially less than the typical anesthesiatime required for open aortic bypass surgical repair, for example.

Use of surgical and/or endovascular grafts have widespread usethroughout the world in vascular surgery. There are many different kindsof vascular graft configurations. Some have supporting framework overtheir entirety, some have only two stents as a supporting framework, andothers simply have the tube-shaped graft material with no additionalsupporting framework, an example that is not relevant to the presentinvention.

One of the most commonly known supporting stent graft frameworks is thatdisclosed in U.S. Pat. Nos. 5,282,824 and 5,507,771 to Gianturco(hereinafter collectively referred to as “Gianturco”). Gianturcodescribes a zig-zag-shaped, self-expanding stent commonly referred to asa z-stent. The stents are, preferably, made of nitinol, but also havebeen made from stainless steel and other biocompatible materials.

There are various features characterizing a stent graft. The firstsignificant feature is the tube of graft material. This tube is commonlyreferred to as the graft and forms the tubular shape that will,ultimately, take the place the diseased portion of the blood vessel. Thegraft is, preferably, made of a woven sheet (tube) of polyester or PTFE.The circumference of the graft tube is, typically, at least as large asthe diameter and/or circumference of the vessel into which the graftwill be inserted so that there is no possibility of blood flowing aroundthe graft (also referred to as endoleak) to either displace the graft orto reapply hemodynamic pressure against the diseased portion of theblood vessel. Accordingly, to so hold the graft, self-expandingframeworks are attached typically to the graft material, whether on theinterior or exterior thereof. Because blood flow within the lumen of thegraft could be impaired if the framework was disposed on the interiorwall of the graft, the framework is connected typically to the exteriorwall of the graft. The ridges formed by such an exterior framework helpto provide a better fit in the vessel by providing a sufficiently unevenouter surface that naturally grips the vessel where it contacts thevessel wall and also provides areas around which the vessel wall canendothelialize to further secure the stent graft in place.

One of the significant dangers in endovascular graft technology is thepossibility of the graft migrating from the desired position in which itis installed. Therefore, various devices have been created to assist inanchoring the graft to the vessel wall.

One type of prior art prosthetic device is a stent graft made of aself-expanding metallic framework. For delivery, the stent graft is,first, radially compressed and loaded into an introducer system thatwill deliver the device to the target area. When the introducer systemholding the stent graft positioned in an appropriate location in thevessel and allowed to open, the radial force imparted by theself-expanding framework is helpful, but, sometimes, not entirelysufficient, in endoluminally securing the stent graft within the vessel.

U.S. Pat. No. 5,824,041 to Lenker et al. (hereinafter “Lenker”)discloses an example of a stent graft delivery system. Lenker disclosesvarious embodiments in which a sheath is retractable proximally over aprosthesis to be released. With regard to FIGS. 7 and 8, Lenker namescomponents 72 and 76, respectively, as “sheath” and“prosthesis-containment sheath.” However, the latter is merely thecatheter in which the prosthesis 74 and the sheath 72 are held. Withregard to FIGS. 9 and 10, the sheath 82 has inner and outer layers 91,92 fluid-tightly connected to one another to form a ballooning structurearound the prosthesis P. This ballooning structure inflates when liquidis inflated with a non-compressible fluid medium and flares radiallyoutward when inflated. With regard to FIGS. 13 to 15, Lenker disclosesthe “sheath” 120, which is merely the delivery catheter, and aneversible membrane 126 that “folds back over itself (everts) as thesheath 120 is retracted so that there are always two layers of themembrane between the distal end of the sheath [120] and the prosthesisP.” Lenker at col. 9, lines 63 to 66. The eversion (peeling back) iscaused by direct connection of the distal end 130 to the sheath 120. TheLenker delivery system shown in FIGS. 19A to 19D holds the prosthesis Pat both ends 256, 258 while an outer catheter 254 is retracted over theprosthesis P and the inner sheath 260. The inner sheath 260 remainsinside the outer catheter 254 before, during, and after retraction.Another structure for holding the prosthesis P at both ends isillustrated in FIGS. 23A and 23B. Therein, the proximal holder havingresilient axial members 342 is connected to a proximal ring structure346. FIGS. 24A to 24C also show an embodiment for holding the prosthesisat both ends inside thin-walled tube 362.

To augment radial forces of stents, some prior art devices have addedproximal and/or distal stents that are not entirely covered by the graftmaterial. By not covering with graft material a portion of theproximal/distal ends of the stent, these stents have the ability toexpand further radially than those stents that are entirely covered bythe graft material. By expanding further, the proximal/distal stent endsbetter secure to the interior wall of the vessel and, in doing so, pressthe extreme cross-sectional surface of the graft ends into the vesselwall to create a fixated blood-tight seal.

One example of such a prior art exposed stent can be found in UnitedStates Patent Publication US 2002/0198587 to Greenberg et al. Themodular stent graft assembly therein has a three-part stent graft: atwo-part graft having an aortic section 12 and an iliac section 14 (withfour sizes for each) and a contralateral iliac occluder 80. FIGS. 1, 2,and 4 to 6 show the attachment stent 32. As illustrated in FIGS. 1, 2,and 4, the attachment stent 32, while rounded, is relatively sharp and,therefore, increases the probability of puncturing the vessel.

A second example of a prior art exposed stent can be found in U.S.Patent Publication 2003/0074049 to Hoganson et al. (hereinafter“Hoganson”), which discloses a covered stent 10 in which the elongatedportions or sections 24 of the ends 20a and 20b extend beyond themarginal edges of the cover 22. See Hoganson at FIGS. 1, 3, 9, 11a, 11b,12a, 12b, and 13. However, these extending exposed edges are triangular,with sharp apices pointing both upstream and downstream with regard to agraft placement location. Such a configuration of the exposed stent 20a,20b increases the possibility of puncturing the vessel. In variousembodiments shown in FIGS. 6a, 6b, 6c, 10, 14a, Hoganson teachescompletely covering the extended stent and, therefore, the absence of astent extending from the cover 22. It is noted that the Hoganson stentis implanted by inflation of a balloon catheter.

Another example of a prior art exposed stent can be found in U.S. Pat.No. 6,565,596 to White et al. (hereinafter “White I”), which uses aproximally extending stent to prevent twisting or kinking and tomaintain graft against longitudinal movement. The extending stent isexpanded by a balloon and has a sinusoidal amplitude greater than thenext adjacent one or two sinusoidal wires. White I indicates that it isdesirable to space wires adjacent upstream end of graft as closetogether as is possible. The stent wires of White I are actually woveninto graft body by piercing the graft body at various locations. SeeWhite I at FIGS. 6 and 7. Thus, the rips in the graft body can lead tothe possibility of the exposed stent moving with respect to the graftand of the graft body ripping further. Between the portions of theextending stent 17, the graft body has apertures.

The stent configuration of U.S. Pat. No. 5,716,393 to Lindenberg et al.is similar to White I in that the outermost portion of the one-piecestent—made from a sheet that is cut/punched and then rolled intocylinder—has a front end with a greater amplitude than the remainingbody of the stent.

A further example of a prior art exposed stent can be found in U.S. Pat.No. 6,524,335 to Hartley et al. (hereinafter “Hartley”). FIGS. 1 and 2of Hartley particularly disclose a proximal first stent 1 extendingproximally from graft proximal end 4 with both the proximal and distalapices narrowing to pointed ends.

Yet another example of a prior art exposed stent can be found in U.S.Pat. No. 6,355,056 to Pinheiro (hereinafter “Pinheiro 1”). Like theHartley exposed stent, Pinheiro discloses exposed stents havingtriangular, sharp proximal apices.

Still a further example of a prior art exposed stent can be found inU.S. Pat. No. 6,099,558 to White et al. (hereinafter “White II”). TheWhite II exposed stent is similar to the exposed stent of White I andalso uses a balloon to expand the stent.

An added example of a prior art exposed stent can be found in U.S. Pat.No. 5,871,536 to Lazarus, which discloses two support members 68longitudinally extending from proximal end to a rounded point. Suchpoints, however, create a very significant possibility of piercing thevessel.

An additional example of a prior art exposed stent can be found in U.S.Pat. No. 5,851,228 to Pinheiro (hereinafter “Pinheiro II”). The PinheiroII exposed stents are similar to the exposed stents of Pinheiro I and,as such, have triangular, sharp, proximal apices.

Still another example of a prior art exposed stent can be found inLenker (U.S. Pat. No. 5,824,041), which shows a squared-off end of theproximal and distal exposed band members 14. A portion of the exposedmembers 14 that is attached to the graft material 18, 20 islongitudinally larger than a portion of the exposed members 14 that isexposed and extends away from the graft material 18, 20. Lenker et al.does not describe the members 14 in any detail.

Yet a further example of a prior art exposed stent can be found in U.S.Pat. No. 5,824,036 to Lauterjung, which, of all of the prior artembodiments described herein, shows the most pointed of exposed stents.Specifically, the proximal ends of the exposed stent are apices pointedlike a minaret. The minaret points are so shaped intentionally to allowforks 300 (see Lauterjung at FIG. 5) external to the stent 154 to pullthe stent 154 from the sheath 302, as opposed to being pushed.

A final example of a prior art exposed stent can be found in U.S. Pat.No. 5,755,778 to Kleshinski. The Kleshinski exposed stents each have twodifferent shaped portions, a triangular base portion and a looped endportion. The totality of each exposed cycle resembles a castellation.Even though the end-most portion of the stent is curved, because it isrelatively narrow, it still creates the possibility of piercing thevessel wall.

All of these prior art stents suffer from the disadvantageouscharacteristic that the relatively sharp proximal apices of the exposedstents have a shape that is likely to puncture the vessel wall.

Devices other than exposed stents have been used to inhibit graftmigration. A second of such devices is the placement of a relativelystiff longitudinal support member longitudinally extending along theentirety of the graft.

The typical stent graft has a tubular body and a circumferentialframework. This framework is not usually continuous. Rather, ittypically takes the form of a series of rings along the tubular graft.Some stent grafts have only one or two of such rings at the proximaland/or distal ends and some have many stents tandemly placed along theentirety of the graft material. Thus, the overall stent graft has an“accordion” shape. During the systolic phase of each cardiac cycle, thehemodynamic pressure within the vessel is substantially parallel withthe longitudinal plane of the stent graft. Therefore, a device havingunsecured stents, could behave like an accordion, or concertina witheach systolic pulsation, and may have a tendency to migrate downstream.(A downstream migration, to achieve forward motion, has a repetitivelongitudinal compression and extension of its cylindrical body.) Suchmovement is entirely undesirable. Connecting the stents with supportalong the longitudinal extent of the device thereof can prevent suchmovement. To provide such support, a second anti-migration device can beembodied as a relatively stiff longitudinal bar connected to theframework.

A clear example of a longitudinal support bar can be found in Pinheiro I(U.S. Pat. No. 6,355,056) and Pinheiro II (U.S. Pat. No. 5,851,228).Each of these references discloses a plurality of longitudinallyextending struts 40 extending between and directly interconnecting theproximal and distal exposed stents 20a, 20b. These struts 40 aredesigned to extend generally parallel with the inner lumen 15 of thegraft 10, in other words, they are straight.

Another example of a longitudinal support bar can be found in U.S. Pat.No. 6,464,719 to Jayaraman. The Jayaraman stent is formed from a grafttube 21 and a supporting sheet 1 made of nitinol. This sheet is bestshown in FIG. 3. The end pieces 11, 13 of the sheet are directlyconnected to one another by wavy longitudinal connecting pieces 15formed by cutting the sheet 1. To form the stent graft, the sheet 1 iscoiled with or around the cylindrical tube 21. See FIGS. 1 and 4.Alternatively, a plurality of connecting pieces 53 with holes at eachend thereof can be attached to a cylindrical fabric tube 51 by stitchingor sutures 57, as shown in FIG. 8. Jayaraman requires more than one ofthese serpentine shaped connecting pieces 53 to provide longitudinalsupport.

United States Patent Publication 2002/0016627 and U.S. Pat. No.6,312,458 to Golds each disclose a variation of a coiled securing member20.

A different kind of supporting member is disclosed in FIG. 8 of U.S.Pat. No. 6,053,943 to Edwin et al.

Like Jayararnan, U.S. Pat. No. 5,871,536 to Lazarus discloses aplurality of straight, longitudinal support structures 38 attached tothe circumferential support structures 36, see FIGS. 1, 6, 7, 8, 10, 11,12, 14. FIG. 8 of Lazarus illustrates the longitudinal supportstructures 38 attached to a distal structure 36 and extending almost allof the way to the proximal structure 36. The longitudinal structures 38,84, 94 can be directly connected to the body 22, 80 and can betelescopic 38, 64.

United States Patent Publication 2003/0088305 to Van Schie et al.(hereinafter “Van Schie”) does not disclose a support bar. Rather, itdiscloses a curved stent graft using an elastic material 8 connected tostents at a proximal end 2 and at a distal end 3 (see FIGS. 1, 2)thereof to create a curved stent graft. Because Van Schie needs tocreate a flexible curved graft, the elastic material 8 is made ofsilicone rubber or another similar material. Thus, the material 8 cannotprovide support in the longitudinal extent of the stent graft.Accordingly, an alternative to the elastic support material 8 is asuture material 25 shown in FIGS. 3 to 6.

SUMMARY OF THE INVENTION

The invention provides a delivery system and method for self-centering aproximal end of a stent graft that overcome the hereinafore-mentioneddisadvantages of the heretofore-known devices and methods of thisgeneral type and that provides a vessel repair device thatimplants/conforms more efficiently within the natural or diseased courseof the aorta by aligning with the natural curve of the aorta, decreasesthe likelihood of vessel puncture, increases the blood-tight vascularconnection, retains the intraluminal wall of the vessel position, ismore resistant to migration, and delivers the stent graft into a curvedvessel while minimizing intraluminal forces imparted during delivery andwhile minimizing the forces needed for a user to deliver the stent graftinto a curved vessel.

With the foregoing and other objects in view, there is provided, inaccordance with the invention, a method for implanting a prosthesiscentrally within a curved lumen, including the steps of loading aprosthesis into a delivery sheath, the prosthesis having a proximal endand the sheath having a distal end, advancing the sheath in a patienttowards the curved lumen to place at least the proximal end within thecurved lumen, and centering the proximal end of the prosthesis and/orthe distal end of the sheath within the curved lumen.

With the objects of the invention in view, there is also provided amethod for centrally implanting a prosthesis, including the steps ofplacing at least a proximal end of a prosthesis in a curved lumen of apatient and centering the proximal end of the prosthesis within thecurved lumen before implanting the prosthesis therein.

With the objects of the invention in view, there is also provided amethod for implanting a prosthesis centrally within a curved lumen,including the steps of loading a prosthesis into a delivery sheath, theprosthesis having a proximal end and the sheath having a distal end, ina first advancing step, advancing the outer catheter containing theinner sheath together towards the curved lumen to a location proximal ofthe curved lumen, and, in a second advancing step, advancing the innersheath containing the prosthesis into the curved lumen to place at leastthe proximal end within the curved lumen while the outer cathetersubstantially remains at the location, centering the proximal end of theprosthesis and/or the distal end of the sheath within the curved lumen,and, after carrying out the centering step, deploying the proximal endof the prosthesis centered within the curved lumen.

With the objects of the invention in view, there is also provided amethod of implanting a prosthesis in a patient at a treatment site,including the steps of providing a prosthesis delivery system with arelatively flexible inner sheath and a relatively stiff outer sheath,loading a prosthesis inside the inner sheath, loading the inner sheathcontaining the prosthesis within the outer sheath, advancing the outersheath in a patient towards the treatment site up to a given position ata distance from the treatment site. While the outer sheath is retainedin the given position, the inner sheath is advanced out from the outersheath to the treatment site to place at least a proximal end of innersheath within the treatment site and the proximal end of the prosthesisand/or the distal end of the inner sheath is centered within the curvedlumen. The inner sheath is retracted to at least partially implant theprosthesis at the treatment site, and, upon completion of prosthesisimplantation, both of the inner and outer sheaths are retracted out fromthe patient.

In accordance with another mode of the invention, after carrying out thecentering step, the prosthesis is deployed centered within the curvedlumen.

In accordance with a further mode of the invention, the proximal end ofthe prosthesis has an orifice defining an inflow plane and a proximalend implantation site of the lumen defines an implant plane, and thecentering step is carried out by substantially aligning the inflow planewith the implant plane.

In accordance with an added mode of the invention, after carrying outthe centering step, the prosthesis is deployed with the inflow planesubstantially aligned with the implant plane.

In accordance with an additional mode of the invention, the centeringstep is carried out by centering at least the distal end of the sheathwithin the curved lumen with a sheath centering device.

In accordance with an additional mode of the invention, the loading stepis carried out by partially collapsing the prosthesis to a size smallerthan an interior of the sheath and inserting the partially collapsedprosthesis into the sheath and the deployment step is carried out byreleasing the prosthesis centered within the curved lumen.

In accordance with yet a further mode of the invention, the sheath isprovided as a relatively flexible inner sheath and the inner sheath isslidably disposed inside a relatively stiff outer catheter.

In accordance with yet an added mode of the invention, the advancingstep is carried out by first advancing the outer catheter containing theinner sheath together towards the curved lumen to a location proximal ofthe curved lumen and subsequently advancing the inner sheath containingthe prosthesis into the curved lumen while the outer cathetersubstantially remains at the location.

In accordance with yet an additional mode of the invention, thecentering step is carried out within a curved portion of an aorta.

In accordance with again another mode of the invention, the prosthesisis provided with a tubular graft body defining an inflow plane and anexit plane and all portions of the stents on the graft body are disposedbetween the inflow plane and the exit plane.

In accordance with again a further mode of the invention, a guidewire isplaced through an implantation site within the curved lumen, theadvancing step is carried out by guiding the delivery sheath containingthe prosthesis along the guidewire, and the centering step is carriedout by moving the proximal end of the prosthesis and/or the distal endof the sheath in a direction away from the guidewire at the implantationsite.

In accordance with again an added mode of the invention, a tip isprovided and the centering of the proximal end of the prosthesis iscarried out with the tip.

In accordance with again an additional mode of the invention, the tip isslidably disposed within the delivery sheath.

In accordance with still a further mode of the invention, the tip isoperatively connected to the delivery sheath to perform the centeringstep with the tip and the sheath.

In accordance with still an added mode of the invention, a tip isslidably disposed within the delivery sheath to place the tip at thedistal end of the sheath, a sheath centering device is connected to thetip through the sheath, and the centering step is carried out with thesheath centering device.

In accordance with still an additional mode of the invention, a tip isprovided with a sheath centering device, the tip is slidably disposedwithin the delivery sheath to place the tip at the distal end of thesheath, and the centering step is carried out by expanding the sheathcentering device out from the tip.

In accordance with another mode of the invention, a sheath centeringdevice is provided at the proximal end of the sheath and the centeringstep is carried out with the sheath centering device.

In accordance with still another mode of the invention, the centeringstep is carried out with a sheath centering device physically separatefrom the sheath.

In accordance with yet another mode of the invention, before carryingout the centering step, a central axis of the sheath centering device isplaced approximately orthogonal to a longitudinal axis of the sheath.

In accordance with an additional mode of the invention, the centeringstep is carried out with a sheath centering device surrounding anexterior of the sheath.

In accordance with again another mode of the invention, the centeringstep is carried out with a sheath centering device disposed between anexterior surface of the sheath and a wall of a lumen in which the sheathis present.

In accordance with a concomitant mode of the invention, the centeringstep is carried out with a sheath centering device disposed within thesheath.

Other features that are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin a delivery system and method for self-centering a proximal end of astent graft, it is, nevertheless, not intended to be limited to thedetails shown because various modifications and structural changes maybe made therein without departing from the spirit of the invention andwithin the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof, will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the present invention, which are believed to be novel,are set forth with particularity in the appended claims. The invention,together with further objects and advantages thereof, may best beunderstood by reference to the following description, taken inconjunction with the accompanying drawings, in the several figures ofwhich like reference numerals identify like elements, and in which:

FIG. 1 is a side elevational view of a stent graft according to theinvention;

FIG. 2 is a side elevational view of a stent of the stent graft of FIG.1 ;

FIG. 3 is a cross-sectional view of the stent of FIG. 2 with differentembodiments of protrusions;

FIG. 4 is a perspective view of a prior art round mandrel for formingprior art stents;

FIG. 5 is a fragmentary, side elevational view of a prior art stent in aportion of a vessel;

FIG. 6 is a perspective view of a dodecahedral-shaped mandrel forforming stents in FIGS. 1 to 3 ;

FIG. 7 is a fragmentary, side elevational view of the stent of FIGS. 1to 3 in a portion of a vessel;

FIG. 8 is a fragmentary, enlarged side elevational view of the proximalend of the stent graft of FIG. 1 illustrating movement of a gimbaledend;

FIG. 9 is a side elevational view of a two-part stent graft according tothe invention;

FIG. 10 is a fragmentary, side elevational view of a delivery systemaccording to the invention with a locking ring in a neutral position;

FIG. 11 is a fragmentary, side elevational view of the delivery systemof FIG. 10 with the locking ring in an advancement position and, asindicated by dashed lines, a distal handle and sheath assembly in anadvanced position;

FIG. 12 is a fragmentary, enlarged view of a sheath assembly of thedelivery system of FIG. 10 ;

FIG. 13 is a fragmentary, enlarged view of an apex capture device of thedelivery system of FIG. 10 in a captured position;

FIG. 14 is a fragmentary, enlarged view of the apex capture device ofFIG. 13 in a released position;

FIG. 15 is a fragmentary, enlarged view of an apex release assembly ofthe delivery system of FIG. 10 in the captured position;

FIG. 16 is a fragmentary, enlarged view of the apex release assembly ofFIG. 15 in the captured position with an intermediate part removed;

FIG. 17 is a fragmentary, enlarged view of the apex release assembly ofFIG. 16 in the released position;

FIG. 18 is a fragmentary, side elevational view of the delivery systemof FIG. 11 showing how a user deploys the prosthesis;

FIG. 19 is a fragmentary cross-sectional view of human arteriesincluding the aorta with the assembly of the present invention in afirst step of a method for inserting the prosthesis according to theinvention;

FIG. 20 is a fragmentary cross-sectional view of the arteries of FIG. 19with the assembly in a subsequent step of the method for inserting theprosthesis;

FIG. 21 is a fragmentary cross-sectional view of the arteries of FIG. 20with the assembly in a subsequent step of the method for inserting theprosthesis;

FIG. 22 is a fragmentary cross-sectional view of the arteries of FIG. 21with the assembly in a subsequent step of the method for inserting theprosthesis;

FIG. 23 is a fragmentary cross-sectional view of the arteries of FIG. 22with the assembly 15 in a subsequent step of the method for insertingthe prosthesis;

FIG. 24 is a fragmentary cross-sectional view of the arteries of FIG. 23with the assembly in a subsequent step of the method for inserting theprosthesis;

FIG. 25 is a fragmentary, diagrammatic, perspective view of the coaxialrelationship of delivery system lumen according to the invention;

FIG. 26 is a fragmentary, cross-sectional view of the apex releaseassembly according to the invention;

FIG. 27 is a fragmentary, side elevational view of the stent graft ofFIG. 1 with various orientations of radiopaque markers according to theinvention;

FIG. 28 is a fragmentary perspective view of the stent graft of FIG. 1with various orientations of radiopaque markers according to theinvention;

FIG. 29 is a perspective view of a distal apex head of the apex capturedevice of FIG. 13 ;

FIG. 30 is a fragmentary side elevational view of the distal apex headof FIG. 29 and a proximal apex body of the apex capture device of FIG.13 with portions of a bare stent in the captured position;

FIG. 31 is a fragmentary, side elevational view of the distal apex headand proximal apex body of FIG. 30 with a portion of the proximal apexbody cut away to illustrate the bare stent in the captured position;

FIG. 32 is a fragmentary side elevational view of the distal apex headand proximal apex body of FIG. 30 in the released position;

FIG. 33 is a fragmentary, cross-sectional view of an embodiment ofhandle assemblies according to the invention;

FIG. 34 is a cross-sectional view of a pusher clasp rotator of thehandle assembly of FIG. 33 ;

FIG. 35 is a plan view of the pusher clasp rotator of FIG. 34 viewedalong line C-C;

FIG. 36 is a plan and partially hidden view of the pusher clasp rotatorof FIG. 34 with a helix groove for a first embodiment of the handleassembly of FIGS. 10, 11, and 18 ;

FIG. 37 is a cross-sectional view of the pusher clasp rotator of FIG. 36along section line A-A;

FIG. 38 is a plan and partially hidden view of the pusher clasp rotatorof FIG. 36 ;

FIG. 39 is a cross-sectional view of the pusher clasp rotator of FIG. 38along section line B-B;

FIG. 40 is a perspective view of a rotator body of the handle assemblyof FIG. 33 ;

FIG. 41 is an elevational and partially hidden side view of the rotatorbody of FIG. 40 ;

FIG. 42 is a cross-sectional view of the rotator body of FIG. 41 alongsection line A-A;

FIG. 43 is an elevational and partially hidden side view of the rotatorbody of FIG. 40 ;

FIG. 44 is an elevational and partially hidden side view of a pusherclasp body of the handle assembly of FIG. 33 ;

FIG. 45 is a cross-sectional view of the pusher clasp body of FIG. 44along section line A-A;

FIG. 46 is a cross-sectional view of the pusher clasp body of FIG. 44along section line B-B;

FIG. 47 is a fragmentary, side elevational view of a portion of thehandle assembly of FIG. 33 with a sheath assembly according to theinvention;

FIG. 48 is an exploded side elevational view of a portion of the handleassembly of FIG. 47 ;

FIG. 49 is a fragmentary elevational and partially hidden side view of ahandle body of 15 the handle assembly of FIG. 33 ;

FIG. 50 is a fragmentary, exploded side elevational view of a portion ofa second embodiment of the handle assembly according to the invention;

FIG. 51 is a fragmentary, side elevational view of the portion of FIG.50 in a neutral position;

FIG. 52 is an exploded view of a first portion of the second embodimentof the handle assembly;

FIG. 53 is a fragmentary, exploded view of a larger portion of thesecond embodiment of the handle assembly as compared to FIG. 52 with thefirst portion and the sheath assembly;

FIG. 54 is perspective view of a clasp body of the second embodiment ofthe handle assembly;

FIG. 55 is an elevational side view of the clasp body of FIG. 54 ;

FIG. 56 is a cross-sectional view of the clasp body of FIG. 55 alongsection line A-A;

FIG. 57 is a plan view of the clasp body of FIG. 54 ;

FIG. 58 is a plan view of the clasp body of FIG. 57 viewed from sectionline B-B;

FIG. 59 is a fragmentary and partially hidden side elevational view of aclasp sleeve of the second embodiment of the handle assembly;

FIG. 60 is a fragmentary, cross-sectional view of a portion the claspsleeve of FIG. 59 along section line A;

FIG. 61 is a fragmentary, cross-sectional view of the clasp sleeve ofFIG. 59 along section line C-C;

FIG. 62 is a fragmentary and partially hidden side elevational view ofthe clasp sleeve of FIG. 59 rotated with respect to FIG. 59 ;

FIG. 63 is a fragmentary, cross-sectional view of the nose cone andsheath assemblies of FIG. 10 ;

FIG. 64 is a fragmentary, perspective view of a portion ofself-alignment configuration according to the invention;

FIG. 65 is a diagrammatic, fragmentary, cross-sectional view of a distalportion of the delivery system with the self-alignment configurationaccording to the invention inside the descending thoracic aorta and withthe self-alignment configuration in an orientation opposite a desiredorientation;

FIG. 66 is a diagrammatic, fragmentary, cross-sectional view of thedistal portion of the delivery system of FIG. 65 with the self-alignmentconfiguration partially inside the descending thoracic aorta andpartially inside the aortic arch and with the self-alignmentconfiguration in an orientation closer to the desired orientation;

FIG. 67 is a diagrammatic, fragmentary, cross-sectional view of thedistal portion of the delivery system of FIG. 65 with the self-alignmentconfiguration primarily inside the aortic arch and with theself-alignment configuration substantially in the desired orientation;

FIG. 68 is a fragmentary, enlarged, partially exploded perspective viewof an alternative embodiment of a distal end of the graft push lumen ofFIG. 25 ;

FIG. 69 is a photograph of a user bending a stent graft assembly arounda curving device to impart a curve to a guidewire lumen therein;

FIG. 70 is a side elevational view of a stent graft according to theinvention;

FIG. 71 is a side elevational view of an alternative embodiment of thestent graft with a clasping stent and a crown stent;

FIG. 72 is a photograph depicting a side view of the stent graft of FIG.71 ;

FIG. 73 is a photograph of a perspective view from a side of a proximalend of the stent graft of FIGS. 1 and 70 with a bare stent protrudingfrom the proximal end thereof;

FIG. 74 is a photograph of an enlarged, perspective view from theinterior of the proximal end of the stent graft of FIG. 71 ;

FIG. 75 is a photograph of a perspective view from a distal end of thestent graft of FIG. 71 with an alternative embodiment of the crown stentwhere less of the stent is attached to the graft;

FIG. 76 is a photograph of a side view of the stent graft of FIG. 71partially withdrawn from a flexible sheath of the delivery systemaccording to the invention with some of the capture stent apicesreleasably held within the apex capture device of the delivery system.

FIG. 77 is a photograph of a perspective view of the captured stentgraft of FIG. 76 from the proximal end thereof and with some of thecapture stent apices releasably held within the apex capture device ofthe delivery system;

FIG. 78 is a photograph of a perspective view from the proximal end ofthe stent graft of FIGS. 1 and 70 deployed in an exemplary vessel;

FIG. 79 is a photograph of a perspective view from the proximal end ofthe stent graft of FIG. 71 deployed in an exemplary vessel;

FIG. 80 is a cross-sectional view of the apex capture assembly of FIGS.13, 14, 29 to 32, and 63 along a plane orthogonal to the longitudinalaxis of the delivery system according to the invention without the innersheath;

FIG. 81 is a fragmentary, cross-sectional view of the apex captureassembly of FIG. 80 along a plane orthogonal to the view plane of FIG.80 and through the longitudinal axis of the delivery system according tothe invention without the inner sheath;

FIG. 82 is a fragmentary, side elevational view of a distal end of thedelivery system according to the invention with the inner sheath in acurved orientation and having an alternative embodiment of a D-shapedmarker thereon;

FIG. 83 is a fragmentary, plan view of the distal end of FIG. 82 viewedfrom above;

FIG. 84 is a fragmentary, plan and partially hidden view of the distalend of FIG. 82 viewed from below with the D-shaped marker on theopposite top side;

FIG. 85 is a fragmentary, elevational view of the distal end of FIG. 82viewed from the top of FIG. 82 and parallel to the longitudinal axis ofthe catheter of the delivery system;

FIG. 86 is a side elevational view of the delivery system according tothe invention with an alternative embodiment of a rotating distalhandle;

FIG. 87 is a fragmentary, cross-sectional view of the rotating distalhandle of FIG. 86 ;

FIG. 88 is a is a fragmentary, cross-sectional view of an alternativeembodiment of the rotating distal handle of FIG. 86 ;

FIG. 89 is a fragmentary, perspective view of the distal end of thedelivery system of FIG. 86 ;

FIG. 90 is a perspective view from the distal side of another embodimentof the delivery system of the invention;

FIG. 91 is a fragmentary, enlarged, exploded, side elevational view ofthe apex release assembly of the delivery system of FIG. 90 ;

FIG. 92 is a fragmentary, enlarged, partially exploded, side elevationalview of the locking knob assembly of the delivery system of FIG. 90 ;

FIG. 93 is a perspective view of a clasp sleeve of a handle assembly ofthe delivery system of FIG. 90 ;

FIG. 94 is an exploded, perspective view of a clasp body assembly of thehandle assembly of FIG. 90 ;

FIG. 95 is an exploded, perspective view of a rotator assembly of thehandle assembly of FIG. 90 ;

FIG. 96 is a perspective view of the rotator assembly of FIG. 95 in anassembled state;

FIG. 97 is a fragmentary, exploded, side elevational view of a deliverysheath of the delivery system of FIG. 90 ;

FIG. 98 is a fragmentary, exploded, side elevational view of thedelivery sheath of FIG. 97 rotated approximately 90 degrees;

FIG. 99 is an enlarged, side elevational view of a portion of thedelivery sheath of FIG. 98 ;

FIG. 100 is a fragmentary, enlarged, side elevational view of the distalend of the delivery system of FIG. 90 ;

FIG. 101 is a fragmentary, partially hidden side elevational view andpartially cross-sectional view of the proximal end of the handleassembly of FIG. 90 with the sheath lumen removed;

FIG. 102 is a fragmentary, cross-sectional view of the proximal end ofthe handle assembly of FIG. 101 ;

FIG. 103 is a fragmentary, enlarged, cross-sectional view of theactuation knob and clasp body assemblies of the handle assembly of FIG.102 ;

FIG. 104 is a fragmentary, enlarged, cross-sectional view of the rotatorassembly of the handle assembly of FIG. 102 ;

FIG. 105 is a fragmentary, further-enlarged, cross-sectional view of therotator assembly of the handle assembly of FIG. 104 ;

FIG. 106 is a fragmentary, transverse cross-sectional view of the handleassembly of the delivery system of FIG. 90 ;

FIG. 107 is a fragmentary, transverse cross-sectional view of the handleassembly of the delivery system of FIG. 90 ;

FIG. 108 is a fragmentary, transverse cross-sectional view of the handleassembly of the delivery system of FIG. 90 ;

FIG. 109 is a fragmentary, transverse cross-sectional view of the handleassembly of the delivery system of FIG. 90 ;

FIG. 110 is a fragmentary, transverse cross-sectional view of the handleassembly of the delivery system of FIG. 90 ;

FIG. 111 is a fragmentary, enlarged, transverse cross-sectional view ofthe handle assembly of FIG. 110 ;

FIG. 112 is a fragmentary, transverse cross-sectional view of the handleassembly of the delivery system of FIG. 90 ;

FIG. 113 is a fragmentary, enlarged transverse cross-sectional view ofthe handle assembly of FIG. 112 ;

FIG. 114 is a fragmentary, transverse cross-sectional view of the handleassembly of the delivery system of FIG. 90 ;

FIG. 115 is a fragmentary, transverse cross-sectional view of the handleassembly of the delivery system of FIG. 90 ;

FIG. 116 is a fragmentary, transverse cross-sectional view of the handleassembly of the delivery system of FIG. 90 ;

FIG. 117 is a fragmentary, transverse cross-sectional view of the handleassembly of the delivery system of FIG. 90 ;

FIG. 118 is a fragmentary, transverse cross-sectional view of the handleassembly of the delivery system of FIG. 90 ;

FIG. 119 is a fragmentary, shaded, cross-sectional view of a distalportion of the handle assembly of FIG. 90 without the proximal handle;

FIG. 120 is a fragmentary, diagrammatic cross-sectional view of thethoracic aorta with a prior art stent graft having an inflow plane at anangle to an implant plane;

FIG. 121 is a fragmentary, diagrammatic cross-sectional view of thethoracic aorta with a stent graft placed according to the invention withthe inflow plane aligned with the implant plane;

FIG. 122 is a diagrammatic, side elevational view of a first exemplaryembodiment of a stent graft centering device according to the invention;

FIG. 123 is a fragmentary, diagrammatic, cross-sectional view of thestent graft centering device of FIG. 122 in an aorta;

FIG. 124 is a fragmentary, diagrammatic, perspective view of a secondexemplary embodiment of a stent graft centering device according to theinvention;

FIG. 125 is a fragmentary, diagrammatic, cross-sectional view of thestent graft centering device of FIG. 124 with one balloon inflated in anaorta;

FIG. 126 is a diagrammatic, plan view of the stent graft centeringdevice of FIG. 124 with three balloons inflated;

FIG. 127 is a diagrammatic, hidden, perspective view of a fourthexemplary embodiment of a stent graft centering device according to theinvention in a first position;

FIG. 128 is a diagrammatic, hidden, perspective view of the stent graftcentering device of FIG. 127 in a second position;

FIG. 129 is a fragmentary, diagrammatic, cross-sectional view of a fifthexemplary embodiment of a stent graft centering device according to theinvention;

FIG. 130 is a fragmentary, diagrammatic, cross-sectional illustrationforces acting upon the stent graft centering device of FIG. 129 ;

FIG. 131 is a fragmentary, diagrammatic, cross-sectional view of a sixthexemplary embodiment of a stent graft centering device according to theinvention in a first position;

FIG. 132 is a fragmentary, diagrammatic, cross-sectional view of thestent graft centering device of FIG. 131 in a second position;

FIG. 133 is a fragmentary, diagrammatic, perspective view of a seventhexemplary embodiment of a stent graft centering device according to theinvention in a closed position;

FIG. 134 is a fragmentary, diagrammatic, perspective view of the stentgraft centering device of FIG. 133 in an open position;

FIG. 135 is a fragmentary, diagrammatic, perspective view of the stentgraft centering device of FIG. 133 in captured state;

FIG. 136 is a fragmentary, diagrammatic, side elevational view of aneighth exemplary embodiment of a stent graft centering device accordingto the invention;

FIG. 137 is a fragmentary, diagrammatic, side elevational view of thestent graft centering device of FIG. 136 in an extended state;

FIGS. 138 and 140 is a fragmentary, diagrammatic, exploded view thestent graft centering device of FIG. 136 ;

FIG. 139 is a fragmentary, diagrammatic, side elevational view the stentgraft centering device of FIG. 136 in a retracted state with a stentcaptured;

FIG. 141 is a fragmentary, diagrammatic, side elevational view the stentgraft centering device of FIG. 136 in an extended centering state with astent captured;

FIG. 142 is a fragmentary, diagrammatic, side elevational view the stentgraft centering device of FIG. 136 in an extended centering state with astent released;

FIG. 143 is a fragmentary, diagrammatic, cross-sectional view of anninth exemplary embodiment of a stent graft centering device accordingto the invention in an aorta;

FIG. 144 is a fragmentary, diagrammatic, side elevational view of atenth exemplary embodiment of a stent graft centering device accordingto the invention in a straight orientation;

FIG. 145 is a fragmentary, diagrammatic, side elevational view of thestent graft centering device of FIG. 144 in a crooked orientation;

FIG. 146 is a fragmentary, diagrammatic, side elevational view of thestent graft centering device of FIG. 144 in a bent orientation;

FIG. 147 is a fragmentary, diagrammatic, cross-sectional view of aneleventh exemplary embodiment of a stent graft centering deviceaccording to the invention in a centered orientation;

FIG. 148 is a fragmentary, diagrammatic, cross-sectional view of thestent graft centering device of FIG. 147 with a delivery system thereinand a stent graft closed;

FIG. 149 is a fragmentary, diagrammatic, cross-sectional view of thestent graft centering device of FIG. 147 with a delivery system thereinand a stent graft open;

FIGS. 150 and 150A are fragmentary, diagrammatic, perspective views ofthe stent graft centering device of FIG. 147 with balloons inflated.

FIG. 151 is a fragmentary, diagrammatic, perspective view of the stentgraft centering device of FIG. 147 with balloons deflated;

FIG. 152 is a fragmentary, diagrammatic, cross-sectional view of atwelfth exemplary embodiment of a stent graft centering device accordingto the invention in an aorta;

FIG. 153 is a fragmentary, diagrammatic, cross-sectional view of thestent graft centering device of FIG. 152 centering a stent graftdelivery device with the stent graft closed;

FIG. 154 is a fragmentary, diagrammatic, cross-sectional view of thestent graft centering device of FIG. 152 centering a stent graftdelivery device with the stent graft open;

FIG. 155 is a fragmentary, diagrammatic, cross-sectional view of thestent graft centering device of FIG. 152 ;

FIG. 156 is a fragmentary, diagrammatic, side elevational view of athirteenth exemplary embodiment of a stent graft centering deviceaccording to the invention;

FIG. 157 is a fragmentary, diagrammatic, side elevational view of aprior art stent graft in an aorta having the inflow plane at an angle tothe implant plane;

FIG. 158 is a fragmentary, diagrammatic, side elevational view of thestent graft centering device of FIG. 156 in an aorta having the inflowplane aligned with the implant plane;

FIG. 159 is a fragmentary, diagrammatic, perspective view of afourteenth exemplary embodiment of a stent graft centering deviceaccording to the invention;

FIG. 160 is a fragmentary, diagrammatic, perspective view of a fifteenthexemplary embodiment of a stent graft centering device according to theinvention;

FIG. 161 is a fragmentary, diagrammatic, perspective view of a controlassembly of the stent graft centering device of FIG. 160 ;

FIG. 162 is a fragmentary, diagrammatic, perspective view of a sixteenthexemplary embodiment of a stent graft centering device according to theinvention in a first configuration;

FIG. 163 is a fragmentary, diagrammatic, perspective view of the stentgraft centering device of FIG. 162 in a second configuration;

FIG. 164 is a fragmentary, diagrammatic, side elevational view of aseventeenth exemplary embodiment of a stent graft centering deviceaccording to the invention in an expanded orientation;

FIG. 165 is a fragmentary, diagrammatic, side elevational view of thestent graft centering device of FIG. 164 in a further expandedorientation;

FIG. 166 is a fragmentary, diagrammatic, side elevational view of thestent graft centering device of FIG. 164 in a contracted orientation;

FIG. 167 is a fragmentary, diagrammatic, side elevational view of thestent graft centering device of FIG. 164 in an open position;

FIG. 167A is a fragmentary, diagrammatic, enlarged side elevational viewof a portion of the stent graft centering device of FIG. 167 in the openposition;

FIG. 168 is a fragmentary, diagrammatic, enlarged, side elevational viewof a portion of the stent graft centering device of FIG. 164 in acaptured position;

FIG. 169 is a fragmentary, diagrammatic, side elevational view of thestent graft centering device of FIG. 167 in a captured position of astent;

FIG. 170 is a fragmentary, diagrammatic, perspective view of aneighteenth exemplary embodiment of a stent graft centering deviceaccording to the invention in a closed orientation;

FIG. 171 is a fragmentary, diagrammatic, perspective view of the stentgraft centering device of FIG. 110 through a stent graft;

FIG. 172 is a fragmentary, diagrammatic, perspective view of the stentgraft centering device of FIG. 171 in an open orientation without thestent graft;

FIG. 173 is a fragmentary, diagrammatic, side elevational view of anineteenth exemplary embodiment of a stent graft centering deviceaccording to the invention in a closed orientation;

FIG. 174 is a fragmentary, diagrammatic, side elevational view of thestent graft centering device of FIG. 173 in an open orientation;

FIG. 175 is a fragmentary, diagrammatic, side elevational view of thestent graft centering device of FIG. 174 through a stent graft; and

FIG. 176 is a fragmentary, diagrammatic, side elevational view of atwentieth exemplary embodiment of a stent graft centering deviceaccording to the invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

While the specification concludes with claims defining the features ofthe invention that are regarded as novel, it is believed that theinvention will be better understood from a consideration of thefollowing description in conjunction with the drawing figures, in whichlike reference numerals are carried forward.

The present invention provides a stent graft, delivery system, andmethod for implanting a prosthesis with a two-part expanding deliverysystem that treats, in particular, thoracic aortic defects from thebrachiocephalic level of the aortic arch distally to a level justsuperior to the celiac axis and provides an endovascular foundation foran anastomosis with the thoracic aorta, while providing an alternativemethod for partial/total thoracic aortic repair by excluding the vesseldefect and making surgical repair of the aorta unnecessary. The stentgraft of the present invention, however, is not limited to use in theaorta. It can be endoluminally inserted in any accessible artery thatcould accommodate the stent graft's dimensions.

Stent Graft

The stent graft according to the present invention provides variousfeatures that, heretofore, have not been applied in the art and,thereby, provide a vessel repair device that implants/conforms moreefficiently within the natural or diseased course of the aorta,decreases the likelihood of vessel puncture, and increases theblood-tight vascular connection, and decreases the probability of graftmobility.

The stent graft is implanted endovascularly before or during or in placeof an open repair of the vessel (i.e., an arch, in particular, theascending and/or descending portion of the aorta) through a deliverysystem described in detail below. The typical defects treated by thestent graft are aortic aneurysms, aortic dissections, and other diseasessuch as penetrating aortic ulcer, coarctation, and patent ductusarteriosus, related to the aorta. When endovascularly placed in theaorta, the stent graft forms a seal in the vessel and automaticallyaffixes itself to the vessel with resultant effacement of thepathological lesion.

Referring now to the figures of the drawings in detail and first,particularly to FIG. 1 thereof, there is shown an improved stent graft 1having a graft sleeve 10 and a number of stents 20. These stents 20 are,preferably, made of nitinol, an alloy having particularly specialproperties allowing it to rebound to a set configuration aftercompression, the rebounding property being based upon the temperature atwhich the alloy exists. For a detailed explanation of nitinol and itsapplication with regard to stents, see, e.g., U.S. Pat. Nos. 4,665,906,5,067,957, and 5,597,378 to Jervis and to Gianturco.

The graft sleeve 10 is cylindrical in shape and is made of a woven graftmaterial along its entire length. The graft material is, preferably,polyester, in particular, polyester referred to under the name DACRON®or other material types like Expanded Polytetrafluoroethylene (“EPTFE”),or other polymeric based coverings. The tubular graft sleeve 10 has aframework of individual lumen-supporting wires each referred to in theart as a stent 20. Connection of each stent 20 is, preferably, performedby sewing a polymeric (nylon, polyester) thread around an entirety ofthe stent 20 and through the graft sleeve 10. The stitch spacings aresufficiently close to prevent any edge of the stent 20 from extendingsubstantially further from the outer circumference of the graft sleeve10 than the diameter of the wire itself. Preferably, the stitches have a0.5 mm to 5 mm spacing.

The stents 20 are sewn either to the exterior or interior surfaces ofthe graft sleeve 10. FIG. 1 illustrates all stents 20, 30 on theexterior surface 16 of the graft sleeve 10. In an exemplarynon-illustrated embodiment, the most proximal 23 and distal stents and abare stent 30 are connected to the interior surface of the graft sleeve10 and the remainder of the stents 20 are connected to the exteriorsurface 16. Another possible non-illustrated embodiment alternatesconnection of the stents 20, 30 to the graft sleeve 10 from the graftexterior surface to the graft interior surface, the alternation havingany periodic sequence.

A stent 20, when connected to the graft sleeve 10, radially forces thegraft sleeve 10 open to a predetermined diameter D. The released radialforce creates a seal with the vessel wall and affixes the graft to thevessel wall when the graft is implanted in the vessel and is allowed toexpand.

Typically, the stents 20 are sized to fully expand to the diameter D ofthe fully expanded graft sleeve 10. However, a characteristic of thepresent invention is that each of the stents 20 and 30 has a diameterlarger than the diameter D of the fully expanded graft sleeve 10. Thus,when the stent graft 1 is fully expanded and resting on the internalsurface of the vessel where it has been placed, each stent 20 isimparting independently a radially directed force to the graft sleeve10. Such pre-compression, as it is referred to herein, is applied (1) toensure that the graft covering is fully extended, (2) to ensuresufficient stent radial force to make sure sealing occurs, (3) to affixthe stent graft and prevent it from kinking, and (4) to affix the stentgraft and prevent migration.

Preferably, each of the stents 20 is formed with a single nitinol wire.Of course other biocompatible materials can be used, for example,stainless steel, biopolymers, cobalt chrome, and titanium alloys.

An exemplary shape of each stent 20 corresponds to what is referred inthe art as a Z-stent, see, e.g., Gianturco (although the shape of thestents 20 can be in any form that satisfies the functions of aself-expanding stent). Thus, the wire forming the stent 20 is a ringhaving a wavy or sinusoidal shape. In particular, an elevational vieworthogonal to the center axis 21 of the stent 20 reveals a shapesomewhere between a triangular wave and a sinusoidal wave as shown inFIG. 2 . In other words, the view of FIG. 2 shows that the stents 20each have alternating proximal 22 and distal 24 apices. Preferably, theapices have a radius r that does not present too great of a pointtowards a vessel wall to prevent any possibility of puncturing thevessel, regardless of the complete circumferential connection to thegraft sleeve 10. In particular, the radius r of curvature of theproximal 22 and distal 24 apices of the stent 20 are, preferably, equal.The radius of curvature r is between approximately 0.1 mm andapproximately 3.0 mm, in particular, approximately 0.5 rom.

Another advantageous feature of a stent lies in extending thelongitudinal profile along which the stent contacts the inner wall of avessel. This longitudinal profile can be explained with reference toFIGS. 3 to 7 .

Prior art stents and stents according to the present invention areformed on mandrels 29, 29′ by winding the wire around the mandrel 29,29′ and forming the apexes 22, 24, 32, 34 by wrapping the wire overnon-illustrated pins that protrude perpendicular from the axis of themandrel. Such pins, if illustrated, would be located in the holesillustrated in the mandrels 29, 29′ of FIGS. 4 and 6 . Prior art stentsare formed on a round mandrel 29 (also referred to as a bar). A stent20′ formed on a round mandrel 29 has a profile that is rounded (see FIG.5 ). Because of the rounded profile, the stent 20′ does not conformevenly against the inner wall of the vessel 2 in which it is inserted.This disadvantage is critical in the area of stent graft 1 sealzones—areas where the ends of the graft 10 need to be laid against theinner wall of the vessel 2. Clinical experience reveals that stents 20′formed with the round mandrel 29 do not lie against the vessel 2;instead, only a mid-section of the stent 20′ rests against the vessel 2,as shown in FIG. 5 . Accordingly, when such a stent 20′ is present ateither of the proximal 12 or distal 14 ends of the stent graft 1, thegraft material flares away from the wall of the vessel 2 into thelumen—a condition that is to be avoided. An example of this flaring canbe seen by comparing the upper and lower portions of the curvedlongitudinal profile of the stent 20′ in FIG. 5 with the linearlongitudinal profile of the vessel 2.

To remedy this problem and ensure co-columnar apposition of the stentand vessel, stents 20 of the present invention are formed on amultiple-sided mandrel. In particular, the stents 20 are formed on apolygonal-shaped mandrel 29′. The mandrel 29′ does not have sharp edges.Instead, it has flat sections and rounded edge portions between therespective flat sections. Thus, a stent formed on the mandrel 29′ willhave a cross-section that is somewhat round but polygonal, as shown inFIG. 3 . The cross-sectional view orthogonal to the center axis 21 ofsuch a stent 20 will have beveled or rounded edges 31 (corresponding tothe rounded edge portions of the mandrel 29′) disposed between flatsides or struts 33 (corresponding to the flat sections of the mandrel29′).

To manufacture the stent 20, apexes of the stents 20 are formed bywinding the wire over non-illustrated pins located on the roundedportions of the mandrel 29′. Thus, the struts 33 lying between theapexes 22, 24, 32, 34 of the stents 20 lie flat against the flat sidesof the mandrel 29′. When so formed on the inventive mandrel 29′, thelongitudinal profile is substantially less rounded than the profile ofstent 20′ and, in practice, is substantially linear.

For stents 20 having six proximal 22 and six distal 24 apices, thestents 20 are formed on a dodecahedron-shaped mandrel 29′ (a mandrelhaving twelve sides), which mandrel 29′ is shown in FIG. 6 . A stent 20formed on such a mandrel 29′ will have the cross-section illustrated inFIG. 3 .

The fourteen-apex stent 20 shown in FIG. 7 illustrates a stent 20 thathas been formed on a fourteen-sided mandrel. The stent 20 in FIG. 7 ispolygonal in cross-section (having fourteen sides) and, as shown in FIG.7 , has a substantially linear longitudinal profile. Clinically, thelinear longitudinal profile improves the stent's 20 ability to conformto the vessel 2 and press the graft sleeve 10 outward in the sealingzones at the extremities of the individual stent 20.

Another way to improve the performance of the stent graft 1 is toprovide the distal-most stent 25 on the graft 10 (i.e., downstream) withadditional apices and to give it a longer longitudinal length (i.e.,greater amplitude) and/or a longer circumferential length. When a stent25 having a longer circumferential length is sewn to a graft, the stentgraft 1 will perform better clinically. The improvement, in part, is dueto a need for the distal portion of the graft material 10 to be pressedfirmly against the wall of the vessel. The additional apices result inadditional points of contact between the stent graft 1 and vessel wall,thus ensuring better apposition to the wall of the vessel and bettersealing of the graft material 10 to the vessel. The increased appositionand sealing substantially improves the axial alignment of the distal end14 of the stent graft 1 to the vessel. As set forth above, each of thestents 20 and 30 has a diameter larger than the diameter D of the fullyexpanded graft sleeve 10. Thus, if the distal stent 25 also has adiameter larger than the diameter D, it will impart a greater radialbias on all 360 degrees of the corresponding section of the graft thanstents not having such an oversized configuration.

A typical implanted stent graft 1 typically does not experience alifting off at straight portions of a vessel because the radial bias ofthe stents acting upon the graft sleeve give adequate pressure to alignthe stent and graft sleeve with the vessel wall. However, when a typicalstent graft is implanted in a curved vessel (such as the aorta), thedistal end of the stent graft 1 does experience a lift off from thevessel wall. The increased apposition and sealing of the stent graft 1according to the present invention substantially decreases theprobability of lift off because the added height and additional apicesenhance the alignment of the stent graft perpendicular to the vesselwall as compared to prior art stent grafts (no lift off occurs).

The number of total apices of a stent is dependent upon the diameter ofthe vessel in which the stent graft 1 is to be implanted. Vessels havinga smaller diameter have a smaller total number of apices than a stent tobe implanted in a vessel having a larger diameter. Table 1 belowindicates exemplary stent embodiments for vessels having differentdiameters. For example, if a vessel has a 26 or 27 mm diameter, then anexemplary diameter of the graft sleeve 10 is 30 mm. For a 30 mm diametergraft sleeve, the intermediate stents 20 will have 5 apices on each side(proximal and distal) for a total of 10 apices. In other words, thestent defines 5 periodic “waves.” The distal-most stent 25, incomparison, defines 6 periodic “waves” and, therefore, has 12 totalapices. It is noted that the distal-most stent 25 in FIG. 1 does nothave the additional apex. While Table 1 indicates exemplary embodiments,these configurations can be adjusted or changed as needed.

TABLE 1 Vessel Diameter Graft Diameter Stent Apices/Side (mm) (mm)(Distal-most Stent #) 19 22 5(5) 20-21 24 5(5) 22-23 26 5(5) 24-25 285(6) 26-27 30 5(6) 28-29 32 6(7) 30-31 34 6(7) 32-33 36 6(7) 34 38 6(7)35-36 40 7(8) 37-38 42 7(8) 39-40 44 7(8) 41-42 46 7(8)

To increase the security of the stent graft 1 in a vessel, an exposed orbare stent 30 is provided on the stent graft 1, preferably, only at theproximal end 12 of the graft sleeve 10—proximal meaning that it isattached to the portion of the graft sleeve 10 from which the bloodflows into the sleeve, i.e., blood flows from the bare stent 30 andthrough the sleeve 10 to the left of FIG. 1 . The bare stent 30 is notlimited to being attached at the proximal end 12. Anothernon-illustrated bare stent can be attached similarly to the distal end14 of the graft sleeve 10.

Significantly, the bare stent 30 is only partially attached to the graftsleeve 10. Specifically, the bare stent 30 is fixed to the graft sleeve10 only at the distal apices 34 of the bare stent 30. Thus, the barestent 30 is partially free to extend the proximal apices 32 away fromthe proximal end of the graft sleeve 10.

The bare stent 30 has various properties, the primary one being toimprove the apposition of the graft material to the contour of thevessel wall and to align the proximal portion of the graft covering inthe lumen of the arch and provide a blood-tight closure of the proximalend 12 of the graft sleeve 10 so that blood does not pass between thevascular inside wall and outer surface 16 of the sleeve 10 (endoleak).

An exemplary configuration for the radius of curvature a of the distalapices 34 is substantially equal to the radius r of the proximal 22 anddistal 24 apices of the stent 20, in particular, it is equal at least tothe radius of curvature r of the proximal apices of the stent 20directly adjacent the bare stent 30. Thus, as shown in FIG. 8 , adistance between the proximal apices 22 of the most proximal stent 23and crossing points of the exposed portions of the bare stent 30 aresubstantially at a same distance from one another all the way around thecircumference of the proximal end 12 of the graft sleeve 10. Preferably,this distance varies based upon the graft diameter. Accordingly, thesinusoidal portion of the distal apices 34 connected to the graft sleeve10 traverse substantially the same path as that of the stent 23 closestto the bare stent 30. Thus, the distance d between the stent 22 and allportions of the bare stent 30 connected to the graft sleeve 10 remainconstant. Such a configuration is advantageous because it maintains thesymmetry of radial force of the device about the circumference of thevessel and also aids in the synchronous, simultaneous expansion of thedevice, thus increasing apposition of the graft material to the vesselwall to induce a proximal seal—and substantially improve the proximalseal—due to increasing outward force members in contact with the vesselwall.

Inter-positioning the stents 23, 30 in phase with one another, createsan overlap, i.e., the apices 34 of the bare stent 30 are positionedwithin the troughs of the stent 23. A further advantage of such aconfiguration is that the overlap provides twice as many points ofcontact between the proximal opening of the graft 10 and the vessel inwhich the stent graft 1 is implanted. The additional apposition pointskeep the proximal opening of the graft sleeve 10 open against the vesselwall, which substantially reduces the potential for endoleaks. Inaddition, the overlap of the stents 23, 30 increases the radial load orresistance to compression, which functionally increases fixation andreduces the potential for device migration.

In contrast to the distal apices 34 of the bare stent 30, the radius ofcurvature_(R) of the proximal apices 32 (those apices that are not sewninto the graft sleeve 10) is significantly larger than the radius ofcurvature a of the distal apices 34. An exemplary configuration for thebare stent apices has a radius approximately equal to 1.5 mm for theproximal apices 32 and approximately equal to 0.5 mm for the distalapices 34. Such a configuration substantially prevents perforation ofthe blood vessel by the proximal apices 32, or, at a minimum, makes ismuch less likely for the bare stent 30 to perforate the vessel becauseof the less-sharp curvature of the proximal apices 32.

The bare stent 30 also has an amplitude greater than the other stents20. Preferably, the peak-to-peak amplitude of the stents 20 isapproximately 1.3 cm to 1.5 cm, whereas the peak-to-peak amplitude ofthe bare stent 30 is approximately 2.5 cm to 4.0 cm. Accordingly, theforce exerted by the bare stent 30 on the inner wall of the aorta (dueto the bare stent 30 expanding to its native position) is spread over alarger surface area. Thus, the bare stent 30 of the present inventionpresents a less traumatic radial stress to the interior of the vesselwall—a characteristic that, while less per square mm than an individualone of the stents 20 would be, is sufficient, nonetheless, to retain theproximal end 12 in position. Simultaneously, the taller configuration ofthe bare stent 30 guides the proximal opening of the stent graft in amore “squared-off” manner. Thus, the proximal opening of the stent graftis more aligned with the natural curvature of the vessel in the area ofthe proximal opening.

As set forth above, because the vessel moves constantly, and due to theconstantly changing pressure imparted by blood flow, any stent graftplaced in the vessel has the natural tendency to migrate downstream.This is especially true when the stent graft 1 has graft sleeve segments18 with lengths defined by the separation of the stents on either end ofthe segment 18, giving the stent graft 1 an accordion, concertina, orcaterpillar-like shape. When such a shape is pulsating with the vesseland while hemodynamic pressure is imparted in a pulsating manner alongthe stent graft from the proximal end 12 to the downstream distal end14, the stent graft 1 has a tendency to migrate downstream in thevessel. It is desired to have such motion be entirely prohibited.

Support along a longitudinal extent of the graft sleeve 10 assists inpreventing such movement. Accordingly, as set forth above, prior artstent grafts have provided longitudinal 15 rods extending in a straightline from one stent to another.

The present invention, however, provides a longitudinal,spiraling/helical support member 40 that, while extending relativelyparallel to the longitudinal axis 11 of the graft sleeve 10, is notaligned substantially parallel to a longitudinal extent of the entiretyof the stent graft 1 as done in the prior art. “Relatively parallel” isreferred to herein as an extent that is more along the longitudinal axis11 of the stent graft 1 than along an axis perpendicular thereto.

Specifically, the longitudinal support member 40 has a somewhat S-turnshape, in that, a proximal portion 42 is relatively parallel to the axis11 of the graft sleeve 10 at a first degree 41 (being defined as adegree of the 360 degrees of the circumference of the graft sleeve 10),and a distal portion 44 is, also, relatively parallel to the axis 11 ofthe tube graft, but at a different second degree 43 on the circumferenceof the graft sleeve 10. The difference between the first and seconddegrees 41, 43 is dependent upon the length L of the graft sleeve 10.For an approximately 20 cm (approx. 8″) graft sleeve, for example, thesecond degree 43 is between 80 and 110 degrees away from the firstdegree 41, in particular, approximately 90 degrees away. In comparison,for an approximately 9 cm (approx. 3.5″) graft sleeve, the second degree43 is between 30 and 60 degrees away from the first degree 41, inparticular, approximately 45 degrees away. As set forth below, thedistance between the first and second degrees 41, 43 is also dependentupon the curvature and the kind of curvature that the stent graft 1 willbe exposed to when in vivo.

The longitudinal support member 40 has a curved intermediate portion 46between the proximal and distal portions 42, 44. By using the word“portion” it is not intended to mean that the rod is in three separateparts (of course, in a particular configuration, a multi-part embodimentis possible). An exemplary embodiment of the longitudinal support member40 is a single, one-piece rod made of stainless steel, cobalt chrome,nitinol, or polymeric material that is shaped as a fully curved helix42, 44, 46 without any straight portion. In an alternative stent graftembodiment, the proximal and distal portions 42, 44 can be substantiallyparallel to the axis 11 of the stent graft 1 and the central portion 46can be helically curved.

One way to describe an exemplary curvature embodiment of thelongitudinal support member 40 can be using an analogy of asymptotes. Ifthere are two asymptotes extending parallel to the longitudinal axis 11of the graft sleeve 10 at the first and second degrees 41, 43 on thegraft sleeve 10, then the proximal portion 42 can be on the first degree41 or extend approximately asymptotically to the first degree 41 and thedistal portion 44 can be on the second degree 43 or extend approximatelyasymptotically to the second degree 43. Because the longitudinal supportmember 40 is one piece in an exemplary embodiment, the curved portion 46follows the natural curve formed by placing the proximal and distalportions 42, 44 as set forth herein.

In such a position, the curved longitudinal support member 40 has acenterline 45 (parallel to the longitudinal axis 11 of the graft sleeve10 halfway between the first and second degrees 41, 43 on the graftsleeve 10). In this embodiment, therefore, the curved portion intersectsthe centerline 45 at approximately 20 to 40 degrees in magnitude,preferably at approximately 30 to 35 degrees.

Another way to describe the curvature of the longitudinal support membercan be with respect to the centerline 45. The portion of thelongitudinal support member 40 between the first degree 41 and thecenterline 45 is approximately a mirror image of the portion of thelongitudinal support member 40 between the second degree 43 and thecenterline 45, but rotated one-hundred eighty degrees (180°) around anaxis orthogonal to the centerline 45. Such symmetry can be referred toherein as “reverse-mirror symmetrical.”

The longitudinal support member 40 is, preferably, sewn to the graftsleeve 10 in the same way as the stents 20. However, the longitudinalsupport member 40 is not sewn directly to any of the stents 20 in theproximal portions of the graft. In other words, the longitudinal supportmember 40 is independent of the proximal skeleton formed by the stents20. Such a configuration is advantageous because an independent proximalend creates a gimbal that endows the stent graft with additionalflexibility. Specifically, the gimbaled proximal end allows the proximalend to align better to the proximal point of apposition, thus reducingthe chance for endoleak. The additional independence from thelongitudinal support member allows the proximal fixation point to beindependent from the distal section that is undergoing related motiondue to the physiological motion of pulsutile flow of blood. Also in anexemplary embodiment, the longitudinal support member 40 is pre-formedin the desired spiral/helical shape (counter-clockwise from proximal todistal), before being attached to the graft sleeve 10.

Because vessels receiving the stent graft 1 are not typically straight(especially the aortic arch), the final implanted position of the stentgraft 1 will, most likely, be curved in some way. In prior art stentgrafts (which only provide longitudinally parallel support rods), thereexist, inherently, a force that urges the rod, and, thereby, the entirestent graft, to the straightened, natural shape of the rod. This forceis disadvantageous for stent grafts that are to be installed in an atleast partly curved manner.

The curved shape of the longitudinal support member 40 according to thepresent invention eliminates at least a majority, or substantially all,of this disadvantage because the longitudinal support member's 40natural shape is curved. Therefore, the support member 40 imparts lessof a force, or none at all, to straighten the longitudinal supportmember 40, and, thereby, move the implanted stent graft in anundesirable way. At the same time, the curved longitudinal supportmember 40 negates the effect of the latent kinetic force residing in theaortic wall that is generated by the propagation of the pulse wave andsystolic blood pressure in the cardiac cycle, which is, then, releasedduring diastole. As set forth in more detail below, the delivery systemof the present invention automatically aligns the stent graft 1 to themost optimal position while traversing the curved vessel in which it isto be implanted, specifically, the longitudinal support member 40 isplaced substantially at the superior longitudinal surface line of thecurved aorta (with respect to anatomical position).

In an exemplary embodiment, the longitudinal support member 40 can becurved in a patient-customized way to accommodate the anticipated curveof the actual vessel in which the graft will be implanted. Thus, thedistance between the first and second degrees 41, 43 will be dependentupon the curvature and the kind of curvature that the stent graft 1 willbe exposed to when in vivo. As such, when implanted, the curvedlongitudinal support member 40 will, actually, exhibit an opposite forceagainst any environment that would alter its conformance to the shape ofits resident vessel's existing course(es).

Preferably, the support member 40 is sewn, in a similar manner as thestents 20, on the 5 outside surface 16 of the graft sleeve 10.

In prior art support rods, the ends thereof are merely a terminating endof a steel or nitinol rod and are, therefore, sharp. Even though theseends are sewn to the tube graft in the prior art, the possibility oftearing the vessel wall still exists. It is, therefore, desirable to notprovide the support rod with sharp ends that could puncture the vesselin which the stent graft is placed.

The two ends of the longitudinal support member 40 of the presentinvention do not end abruptly. Instead, each end of the longitudinalsupport member loops 47 back upon itself such that the end of thelongitudinal support member along the axis of the stent graft is notsharp and, instead, presents an exterior of a circular or oval shapewhen viewed from the ends 12, 14 of the graft sleeve 10. Such aconfiguration substantially prevents the possibility of tearing thevessel wall and also provides additional longitudinal support at theoval shape by having two longitudinally extending sides of the oval 47.

In addition, in another embodiment, the end of the longitudinal supportmember may be connected to the second proximal stent 28 and to the mostdistal stent. This configuration would allow the longitudinal supportmember to be affixed to stent 28 (see FIG. 1 ) and the most distal stentfor support while still allowing for the gimbaled feature of theproximal end of the stent graft to be maintained.

A significant feature of the longitudinal support member 40 is that theends of the longitudinal support member 40 may not extend all the way tothe two ends 12, 14 of the graft sleeve 10. Instead, the longitudinalsupport member 40 terminates at or prior to the second-to-last stent 28at the proximal end 12, and, if desired, prior to the second-to-laststent 28′ at the distal end 14 of the graft sleeve 10. Such an endingconfiguration (whether proximal only or both proximal and distal) ischosen for a particular reason—when the longitudinal support member 40ends before either of the planes defined by cross-sectional lines 52,52′, the sleeve 10 and the stents 20 connected thereto respectively formgimbaled portions 50, 50′. In other words, when a grasping force actingupon the gimbaled ends 50, 50′ moves or pivots the cross-sectional planedefining each end opening of the graft sleeve 10 about the longitudinalaxis 11 starting from the planes defined by the cross-sectional lines52, 52′, then the moving portions 50, 50′ can be oriented at any angle γabout the center of the circular opening in all directions (360degrees), as shown in FIG. 8 . The natural gimbal, thus, allows the ends50, 50′ to be inclined in any radial direction away from thelongitudinal axis 11.

Among other things, the gimbaled ends 50, 50′ allow each end opening todynamically align naturally to the curve of the vessel in which it isimplanted. A significant advantage of the gimbaled ends 50, 50′ is thatthey limit propagation of the forces acting upon the separate parts.Specifically, a force that, previously, would act upon the entirety ofthe stent graft 1, in other words, both the end portions 50, 50′ and themiddle portion of the stent graft 1 (i.e., between planes 52, 52′), nowprincipally acts upon the portion in which the force occurs. Forexample, a force that acts only upon one of the end portions 50, 50′substantially does not propagate into the middle portion of the stentgraft 1 (i.e., between planes 52, 52′). More significantly, however,when a force acts upon the middle portion of the stent graft 1 (whethermoving longitudinally, axially (dilation), or in a torqued manner), theends 50, 50′, because they are gimbaled, remain relatively completelyaligned with the natural contours of the vessel surrounding therespective end 50,′50′ and have virtually none of the force transferredthereto, which force could potentially cause the ends to grate, rub, orshift from their desired fixed position in the vessel. Accordingly, thestent graft ends 50,50′ remain fixed in the implanted position andextend the seating life of the stent graft 1.

Another advantage of the longitudinal support member 40 is that itincreases the columnar strength of the graft stent 1. Specifically, thematerial of the graft sleeve can be compressed easily along thelongitudinal axis 11, a property that remains true even with thepresence of the stents 20 so long as the stents 20 are attached to thegraft sleeve 10 with a spacing between the distal apices 24 of one stent20 and the proximal apices 22 of the next adjacent stent 20. This isespecially true for the amount of force imparted by the flow of bloodalong the extent of the longitudinal axis 11. However, with thelongitudinal support member 40 attached according to the presentinvention, longitudinal strength of the stent graft 1 increases toovercome the longitudinal forces imparted by blood flow.

Another benefit imparted by having such increased longitudinal strengthis that the stent graft 1 is further prevented from migrating in thevessel because the tube graft is not compressing and expanding in anaccordion-like manner—movement that would, inherently, cause graftmigration.

A further measure for preventing migration of the stent graft 1 is toequip at least one of any of the individual stents 20, 30 or thelongitudinal support member 40 with protuberances 60, such as barbs orhooks (FIG. 3 ). See, e.g., United States Patent Publication2002/0052660 to Greenhalgh. In an exemplary embodiment of the presentinvention, the stents 20, 30 are secured to the outer circumferentialsurface 16 of the graft sleeve 10. Accordingly, if the stents 20 (orconnected portions of stent 30) have protuberances 60 protrudingoutwardly, then such features would catch the interior wall of thevessel and add to the prevention of stent graft 1 migration. Such anembodiment can be preferred for aneurysms but is not preferred for thefragile characteristics of dissections because such protuberances 60 canexcoriate the inner layer(s) of the vessel and cause leaks betweenlayers, for example.

As shown in FIG. 9 , the stent graft 1 is not limited to a single graftsleeve 10. Instead, the entire stent graft can be a first stent graft100 having all of the features of the stent graft 1 described above anda second stent graft 200 that, instead of having a circular extremeproximal end 12, as set forth above, has a proximal end 212 with a shapefollowing the contour of the most proximal stent 220 and is slightlylarger in circumference than the distal circumference of the first stentgraft 100. Therefore, an insertion of the proximal end 212 of the secondstent graft 200 into the distal end 114 of the first stent graft 100results, in total, in a two-part stent graft. Because blood flows fromthe proximal end 112 of the first stent graft 100 to the distal end 214of the second stent graft 200, it is preferable to have the first stentgraft 100 fit inside the second stent graft 200 to prevent blood fromleaking out therebetween. This configuration can be achieved byimplanting the devices in reverse order (first implant graft 200 and,then, implant graft 100. Each of the stent grafts 100, 200 can have itsown longitudinal support member 40 as needed.

It is not significant if the stent apices of the distal-most stent ofthe first stent graft 100 are not aligned with the stent apices of theproximal-most stent 220 of the second stent graft 200. What is importantis the amount of junctional overlap between the two grafts 100, 200.

Delivery System

As set forth above, the prior art includes many different systems forendoluminally delivering a prosthesis, in particular, a stent graft, toa vessel. Many of the delivery systems have similar parts and most areguided along a guidewire that is inserted, typically, through aninsertion into the femoral artery near a patient's groin prior to use ofthe delivery system. To prevent puncture of the arteries leading to andincluding the aorta, the delivery system is coaxially connected to theguidewire and tracks the course of the guidewire up to the aorta. Theparts of the delivery system that will track over the wire are,therefore, sized to have an outside diameter smaller than the insidediameter of the femoral artery of the patient. The delivery systemcomponents that track over the guidewire include the stent graft and aremade of a series of coaxial lumens referred to as catheters and sheaths.The stent graft is constrained, typically, by an outer catheter,requiring the stent graft to be compressed to fit inside the outercatheter. Doing so makes the portion of the delivery system thatconstrains the stent graft very stiff, which, therefore, reduces thatportion's flexibility and makes it difficult for the delivery system totrack over the guidewire, especially along curved vessels such as theaortic arch. In addition, because the stent graft exerts very highradial forces on the constraining catheter due to the amount that itmust be compressed to fit inside the catheter, the process of deployingthe stent graft by sliding the constraining catheter off of the stentgraft requires a very high amount of force, typically referred to as adeployment force. Also, the catheter has to be strong enough toconstrain the graft, requiring it to be made of a rigid material. If therigid material is bent, such as when tracking into the aortic arch, therigid material tends to kink, making it difficult if not impossible todeploy the stent graft.

Common features of vascular prosthesis delivery systems include atapered nose cone fixedly connected to a guidewire lumen, which has aninner diameter substantially corresponding to an outer diameter of theguidewire such that the guidewire lumen slides easily over and along theguidewire. A removable, hollow catheter covers and holds a compressedprosthesis in its hollow and the catheter is fixedly connected to theguidewire lumen. Thus, when the prosthesis is in a correct position forimplantation, the physician withdraws the hollow catheter to graduallyexpose the self-expanding prosthesis from its proximal end towards itsdistal end. When the catheter has withdrawn a sufficient distance fromeach portion of the expanding framework of the prosthesis, the frameworkcan expand to its native position, preferably, a position that has adiameter at least as great as the inner diameter of the vessel wall to,thereby, tightly affix the prosthesis in the vessel When the catheter isentirely withdrawn from the prosthesis and, thereby, allows theprosthesis to expand to the diameter of the vessel, the prosthesis isfully expanded and connected endoluminally to the vessel along theentire extent of the prosthesis, e.g., to treat a dissection. Whentreating an aneurysm, for example, the prosthesis is in contact with thevessel's proximal and distal landing zones when completely released fromthe catheter. At such a point in the delivery, the delivery system canbe withdrawn from the patient. The prosthesis, however, cannot bereloaded in the catheter if implantation is not optimal.

The aorta usually has a relatively straight portion in the abdominalregion and in a lower part of the thoracic region. However, in the upperpart of the thoracic region, the aorta is curved substantially,traversing an upside-down U-shape from the back of the heart over to thefront of the heart. As explained above, prior art delivery systems arerelatively hard and inflexible (the guidewire/catheter portion of theprior art delivery systems). Therefore, if the guidewire/catheter musttraverse the curved portion of the aorta, it will kink as it is curvedor it will press against the top portion of the aortic curve, possiblypuncturing the aorta if the diseased portion is located where theguidewire/catheter is exerting its force. Such a situation must beavoided at all costs because the likelihood of patient mortality ishigh. The prior art does not provide any way for substantially reducingthe stress on the curved portion of the aorta or for making theguidewire/catheter sufficiently flexible to traverse the curved portionwithout causing damage to the vessel.

The present invention, however, provides significant features not foundin the prior art that assist in placing a stent graft in a curvedportion of the aorta in a way that substantially reduces the stress onthe curved portion of the aorta and substantially reduces the insertionforces needed to have the compressed graft traverse the curved portionof the aorta. As set forth above, the longitudinal support member 40 ispre-formed in a desired spiral/helical shape before being attached tothe graft sleeve 10 and, in an exemplary embodiment, is curved in apatient-customized way to accommodate the anticipated curve of theactual vessel in which the graft will be implanted. As such, optimalpositioning of the stent graft 1 occurs when the longitudinal supportmember 40 is placed substantially at the superior longitudinal surfaceline of the curved aorta (with respect to anatomical position). Suchplacement can be effected in two ways. First, the stent graft 1, thesupport member 40, or any portion of the delivery system that is nearthe target site can be provided with radiopaque markers that aremonitored by the physician and used to manually align the support member40 in what is perceived as an optimal position. The success of thisalignment technique, however, is dependent upon the skill of thephysician. Second, the delivery system can be made to automaticallyalign the support member 40 at the optimal position. No such systemexisted in the prior art. However, the delivery system of the presentinvention provides such an alignment device, thereby, eliminating theneed for physician guesswork as to the three-dimensional rotationalposition of the implanted stent graft 1. This alignment device isexplained in further detail below with respect to FIGS. 64 to 67 .

The delivery system of the present invention also has a very simple touse handle assembly. The handle assembly takes advantage of the factthat the inside diameter of the aorta is substantially larger that theinside diameter of the femoral arteries. The present invention,accordingly, uses a two-stage approach in which, after the device isinserted in through the femoral artery and tracks up into the abdominalarea of the aorta (having a larger diameter (see FIG. 19 ) than thefemoral artery), a second stage is deployed (see FIG. 20 ) allowing asmall amount of expansion of the stent graft while still constrained ina sheath; but this sheath, made of fabric/woven polymer or similarflexible material, is very flexible. Such a configuration gives thedelivery system greater flexibility for tracking, reduces deploymentforces because of the larger sheath diameter, and easily overcome kinksbecause the sheath is made of fabric.

To describe the delivery system of the present invention, the method foroperating the delivery assembly 600 will be described first inassociation with FIGS. 10, 11, and 12 . Thereafter, the individualcomponents will be described to allow a better understanding of how eachstep in the process is effected for delivering the stent graft 1 to anyportion of the aorta 700 (see FIGS. 19 to 24 ), in particular, thecurved portion 710 of the aorta.

Initially, the distal end 14 of the stent graft 1 is compressed andplaced into a hollow, cup-shaped, or tubular-shaped graft holdingdevice, in particular, the distal sleeve 644 (see, e.g., FIG. 25 ). Atthis point, it is noted that the convention for indicating directionwith respect to delivery systems is opposite that of the convention forindicating direction with respect to stent grafts. Therefore, theproximal direction of the delivery system is that portion closest to theuser/physician employing the system and the distal direction correspondsto the portion farthest away from the user/physician, i.e., towards thedistal-most nose cone 632.

The distal sleeve 644 is fixedly connected to the distal end of thegraft push lumen 642, which lumen 642 provides an end face for thedistal end 14 of the stent graft 1. Alternatively, the distal sleeve 644can be removed entirely. In such a configuration, as shown in FIG. 12 ,for example, the proximal taper of the inner sheath 652 can provide themeasures for longitudinally holding the compressed distal end of thegraft 1. If the sleeve 644 is removed, it is important to prevent thedistal end 14 of the stent graft 1 from entering the space between theinterior surface of the hollow sheath lumen 654 and the exterior surfaceof the graft push lumen 642 slidably disposed in the sheath lumen 654.Selecting a radial thickness of the space to be less than the diameterof the wire making up the stent 20, 30 (in particular, no greater thanhalf a diameter thereof) insures reliable movement of the distal end 14of the stent graft 1. In another alternative configuration shown in FIG.68 , the distal sleeve 644 can be a disk-shaped buttress 644 present atthe distal end of the graft push lumen 642. An example configuration canprovide the buttress 644 with a hollow proximal insertion peg 6442, ahollow distal stiffening tube 6444, and an intermediate buttress wall6446. The buttress 644 is concentric to the center axis of the deliverysystem 600 and allows the co-axial guidewire lumen 620 and apex releaselumen 640 to pass therethrough. The peg 6442 allows for easy connectionto the graft push lumen 643. The stiffening tube 64 creates a transitionin stiffness from the graft push lumen 642 to the apex release lumen 620and guidewire lumen 640 and provides support to the lumen 620, 640located therein. Such a transition in stiffness reduces any possibilityof kinking at the distal end of the graft push lumen 642 and aids intransferring force from the graft push lumen 642 to the lumen therein620, 640 when all are in a curved orientation. The buttress wall 6446provides a flat surface that will contact the distal-end-facing side ofthe stent graft 1 and can be used to push the stent graft distally whenthe graft push lumen 642 is moved distally. The alternativeconfiguration of the buttress 644 insures that the stent graft 1 doesnot become impinged within the graft push lumen 642 and the lumentherein 620, 640 when these components are moved relative to each other.

As set forth in more detail below, each apex 32 of the bare stent 30 is,then, loaded into the apex capture device 634 so that the stent graft 1is held at both its proximal and distal ends. The loaded distal end 14,along with the distal sleeve 644 and the graft push lumen 642, are, inturn, loaded into the inner sheath 652, thus, further compressing theentirety of the stent graft 1. The captured bare stent 30, along withthe nose cone assembly 630 (including the apex capture device 634), isloaded until the proximal end of the nose cone 632 rests on the distalend of the inner sheath 652. The entire nose cone assembly 630 andsheath assembly 650 is, then, loaded proximally into the rigid outercatheter 660, further compressing the stent graft 1 (resting inside theinner sheath 652) to its fully compressed position for later insertioninto a patient. See FIG. 63 .

The stent graft 1 is, therefore, held both at its proximal and distalends and, thereby, is both pushed and pulled when moving from a firstposition (shown in FIG. 19 and described below) to a second position(shown in FIG. 21 and described below). Specifically, pushing isaccomplished by the non-illustrated interior end face of the hollowdistal sleeve 644 (or the taper 653 of the inner sheath 652) and pullingis accomplished by the hold that the apex capture device 634 has on theapices 32 of the bare stent 30.

The assembly 600 according to the present invention tracks along aguidewire 610 already inserted in the patient and extending through theaorta and up to, but not into, the left ventricle of the heart 720.Therefore, a guidewire 610 is inserted through the guidewire lumen 620starting from the nose cone assembly 630, through the sheath assembly650, through the handle assembly 670, and through the apex releaseassembly 690. The guidewire 610 extends out the proximal-most end of theassembly 600. The guidewire lumen 620 is coaxial with the nose coneassembly 630, the sheath assembly 650, the handle assembly 670, and theapex release assembly 690 and is the innermost lumen of the assembly 600immediately surrounding the guidewire 610.

Before using the delivery system assembly 600, all air must be purgedfrom inside the assembly 600. Therefore, a liquid, such as sterileU.S.P. saline, is injected through a non-illustrated tapered luerfitting to flush the guidewire lumen at a non-illustrated purge portlocated near a proximal end of the guidewire lumen. Second, saline isalso injected through the luer fitting 612 of the lateral purge-port(see FIG. 11 ), which liquid fills the entire internal co-axial space ofthe delivery system assembly 600. It may be necessary to manipulate thesystem to facilitate movement of the air to be purged to the highestpoint of the system.

After purging all air, the system can be threaded onto the guidewire andinserted into the patient. Because the outer catheter 660 has apredetermined length, the fixed front handle 672 can be disposedrelatively close to the entry port of the femoral artery. It is noted,however, that the length of the outer catheter 660 is sized such that itwill not have the fixed proximal handle 672 directly contact the entryport of the femoral artery in a patient who has the longest distancebetween the entry port and the thoracic/abdominal junction 742, 732 ofthe aorta expected in a patient (this distance is predetermined). Thus,the delivery assembly 600 of the present invention can be used withtypical anatomy of the patient. Of course, the assembly 600 can be sizedto any usable length.

The nose cone assembly 630 is inserted into a patient's femoral arteryand follows the guidewire 610 until the nose cone 632 reaches the firstposition at least to a level of the celiac axis and possibly further butnot into the intended stent graft deployment site, which would preventdeployment of at least the downstream end of the stent graft. The firstposition is shown in FIG. 19 . The nose cone assembly 630 is radiopaque,whether wholly or partially, to enable the physician to determinefluoroscopically, for example, that the nose cone assembly 630 is in thefirst position. For example, the nose cone 632 can have a radiopaquemarker 631 anywhere thereon or the nose cone 632 can be entirelyradiopaque.

FIGS. 19 to 24 illustrate the catheter 660 extending approximately up tothe renal arteries. However, the catheter 660 of the present inventionis configured to travel up to at least the celiac axis (not shown inFIGS. 19 to 24 ). As used herein, the celiac axis is to be definedaccording to common medical terms. In a simplistic definition, theceliac axis is a plane that intersects and is parallel to a central axisof a patient's celiac at the intersection of the celiac and the aortaand, therefore, this plane is approximately orthogonal to thelongitudinal axis of the abdominal/thoracic aorta at the point where theceliac intersects the aorta. Therefore, with respect to extension of thecatheter 660 into the aorta, it is extended into the aorta up to but notpast the intended downstream end of the implant. After arriving at thisdistal-most position, the distal end of the catheter 660 remainssubstantially steady along the longitudinal axis of the aorta untilafter the stent graft 1 is implanted (see FIG. 24 ) and the entiredelivery system is to be removed from the patient. While the deliverysystem of the present invention can be retracted in the orientationshown in FIG. 24 except for one difference (the bare stent 32 is openand the apex release device 634 is released from compressing the barestent 32), the preferred embodiment for removal of the catheter 660 fromthe aorta after implantation of the stent graft 1 occurs with referenceto the condition shown In FIG. 19 —where all of the interior lumens 620,640, 642, 654 are retracted inside the catheter 660 and the nose cone631 is in contact with the distal end of the catheter 660.

After the nose cone assembly 630 is in the first position shown in FIG.19 , the locking knob or ring 676 is placed from its neutral positioninto its advancement position. As will be described below, placing thelocking knob 676 into its advancement position A allows both the nosecone assembly 630 and the internal sheath assembly 650 to move as onewhen the proximal handle 678 is moved in either the proximal or distaldirections because the locking knob 676 radially locks the graft pushlumen 642 to the lumens of the apex release assembly 690 (including theguidewire lumen 620 and an apex release lumen 640). The locking knob 676is fixedly connected to a sheath lumen 654.

Before describing how various embodiments of the handle assembly 670function, a summary of the multi-lumen connectivity relationships,throughout the neutral, advancement, and deployment positions, isdescribed.

When the locking ring is in the neutral position, the pusher claspspring 298 shown in FIG. 48 and the distal clasp body spring 606 shownin FIG. 52 are both disengaged. This allows free movement of the graftpush lumen 642 with the guidewire lumen 620 and the apex release lumen640 within the handle body 674.

When the locking knob 676 is moved into the advancement position, thepusher clasp spring 298 shown in FIG. 48 is engaged and the distal claspbody spring 606 shown in FIG. 52 is disengaged. The sheath lumen 654(fixedly attached to the inner sheath 652) is, thereby, locked to thegraft push lumen 642 (fixedly attached to the distal sleeve 644) sothat, when the proximal handle 678 is moved toward the distal handle672, both the sheath lumen 654 and the graft push lumen 642 move as one.At this point, the graft push lumen 642 is also locked to both theguidewire lumen 620 and the apex release lumen 640 (which are locked toone another through the apex release assembly 690 as set forth in moredetail below). Accordingly, as the proximal handle 678 is moved to thesecond position, shown with dashed lines in FIG. 11 , the sheathassembly 650 and the nose cone assembly 630 progress distally out of theouter catheter 660 as shown in FIGS. 20 and 21 and with dashed lines inFIG. 11 .

At this point, the sheath lumen 654 needs to be withdrawn from the stentgraft 1 to, thereby, expose the stent graft 1 from its proximal end 12to its distal end 14 and, ultimately, entirely off of its distal end 14.Therefore, movement of the locking knob 676 into the deployment positionD will engage the distal clasp body spring 606 shown in FIG. 52 anddisengage the pusher clasp spring 298 shown in FIG. 48 . Accordingly,the graft push lumen 642 along with the guidewire lumen 620 and the apexrelease lumen 640 are locked to the handle body 674 so as not to movewith respect to the handle body 674. The sheath lumen 654 is unlockedfrom the graft push lumen 642. Movement of the distal handle 678 back tothe third position (proximally), therefore, pulls the sheath lumen 654proximally, thus, proximally withdrawing the inner sheath 652 from thestent graft 1.

At this point, the delivery assembly 600 only holds the bare stent 30 ofthe stent graft 1. Therefore, final release of the stent graft 1 occursby releasing the bare stent 30 from the nose cone assembly 630, which isaccomplished using the apex release assembly 690 as set forth below.

In order to explain how the locking and releasing of the lumen occur asset forth above, reference is made to FIGS. 33 to 62 .

FIG. 33 is a cross-sectional view of the proximal handle 678 and thelocking knob 676. A pusher clasp rotator 292 is disposed between a claspsleeve 614 and the graft push lumen 642. A specific embodiment of thepusher clasp rotator 292 is illustrated in FIGS. 34 through 39 . Alsodisposed between the clasp rotator 292 and the graft push lumen 642 is arotator body 294, which is directly adjacent the graft push lumen 642. Aspecific embodiment of the rotator body 294 is illustrated in FIGS. 40through 43 . Disposed between the rotator body 294 and the sheath lumen654 is a pusher clasp body 296, which is fixedly connected to therotator body 294 and to the locking knob 676. A specific embodiment ofthe pusher clasp body 296 is illustrated in FIGS. 44 through 46 . Apusher clasp spring 298 operatively connects the pusher clasp rotator292 to the rotator body 294 (and, thereby, the pusher clasp body 296).

An exploded view of these components is presented in FIG. 48 , where anO-ring 293 is disposed between the rotator body 294 and the pusher claspbody 296. As shown in the plan view of FIG. 47 , a crimp ring 295connects the sheath lumen 654 to the distal projection 297 of the pusherclasp body 296. A hollow handle body 674 (see FIGS. 10, 11, and 33 ), onwhich the proximal handle 678 and the locking knob 676 are slidablymounted, holds the pusher clasp rotator 292, the rotator body 294, thepusher clasp body 296, and the pusher clasp spring 298 therein. Thisentire assembly is rotationally mounted to the distal handle 672 forrotating the stent graft 1 into position (see FIGS. 23 and 24 and theexplanations thereof below). A specific embodiment of the handle body674 is illustrated in FIG. 49 .

A setscrew 679 extends from the proximal handle 678 to contact alongitudinally helixed groove in the pusher clasp rotator 292 (shown inFIGS. 36 and 38 ). Thus, when moving the proximal handle 678 proximallyor distally, the pusher clasp rotator 292 rotates clockwise orcounter-clockwise.

An alternative embodiment of the locking knob 676 is shown in FIG. 50 etseq. in which, instead of applying a longitudinal movement to rotate thepusher clasp spring 298 through the cam/follower feature of the proximalhandle 678 and pusher clasp rotator 292, a rotating locking knob 582 islocated at the proximal end of the handle body 674. The knob 582 hasthree positions that are clearly shown in FIG. 51 : a neutral positionN, an advancement position A, and a deployment position D. The functionsof these positions N, A, D correspond to the positions N, A, D of thelocking knob 676 and the proximal handle 678 as set forth above.

In the alternative embodiment, a setscrew or pin 584 is threaded intothe clasp sleeve 614 through a slot 675 in the handle body 674 andthrough a slot 583 in the knob 582 to engage the locking knob 582. Thedepth of the pin 584 in the clasp sleeve 614 is small because of therelatively small thickness of the clasp sleeve 614. To provideadditional support to the pin 584 and prevent it from coming out of theclasp sleeve 614, an outer ring 6144 is disposed on the exterior surfaceof the proximal end of the clasp sleeve 614. Because of the x-axisorientation of the slot 583 in the knob 582 and the y-axis orientationof the slot 675 in the handle body 674, when the knob 582 is slid overthe end of the handle body 674 and the setscrew 584 is screwed into theclasp sleeve 614, the knob 582 is connected fixedly to the handle body674. When the locking knob 582 is, thereafter, rotated between theneutral N, advancement A, and deployment D positions, the clasp sleeve614 rotates to actuate the spring lock (see FIGS. 48 and 52 ).

A setscrew 586, shown in FIG. 53 , engages a groove 605 in the proximalclasp assembly 604 to connect the proximal clasp assembly 604 to theclasp sleeve 614 but allows the clasp sleeve 614 to rotate around theclasp body 602. The clasp sleeve 614 is shown in FIGS. 50 and 53 and, inparticular, in FIGS. 59 to 62 . The proximal clasp assembly 604 of FIG.53 is more clearly shown in the exploded view of FIG. 52 . The proximalclasp assembly 604 is made of the components including a distal claspbody spring 606, a locking washer 608, a fastener 603 (in particular, ascrew fitting into internal threads of the proximal clasp body 602), anda proximal clasp body 602. The proximal clasp body 602 is shown, inparticular, in FIGS. 54 through 58 . The proximal clasp assembly 604 isconnected fixedly to the handle body 674, preferably, with a screw 585shown in FIG. 50 and hidden from view in FIG. 51 under knob 582.

The handle body 674 has a position pin 592 for engaging in positionopenings at the distal end of the locking knob 582. The position pin 592can be a setscrew that only engages the handle body 674. When thelocking knob 582 is pulled slightly proximally, therefore, the knob canbe rotated clockwise or counter-clockwise to place the pin 592 into theposition openings corresponding to the advancement A, neutral N, anddeployment D positions.

As shown in FIG. 18 , to begin deployment of the stent graft 1, theuser/physician grasps both the distal handle 672 and the proximal handle678 and slides the proximal handle 678 towards the distal handle 672 inthe direction indicated by arrow A. This movement, as shown in FIGS. 19to 21 , causes the flexible inner sheath 652, holding the compressedstent graft 1 therein, to emerge progressively from inside the outercatheter 660. Such a process allows the stent graft 1, while constrainedby the inner sheath 652, to expand to a larger diameter shown in FIG. 12, this diameter being substantially larger than the inner diameter ofthe outer catheter 660 but smaller than the inner diameter of the vesselin which it is to be inserted. Preferably, the outer catheter 660 ismade of a polymer (co-extrusions or teflons) and the inner sheath 652 ismade of a material, such as a fabric/woven polymer or other similarmaterial. Therefore, the inner sheath 652 is substantially more flexiblethan the outer catheter 660.

It is noted, at this point, that the inner sheath 652 contains a taper653 at its proximal end, distal to the sheath's 652 connection to thesheath lumen 654 (at which connection the inner sheath 652 has a similardiameter to the distal sleeve 644 and works in conjunction with thedistal sleeve 644 to capture the distal end 14 of the stent graft 1. Thetaper 653 provides a transition that substantially prevents any kinkingof the outer catheter 660 when the stent graft 1 is loaded into thedelivery assembly 600 (as in the position illustrated in FIGS. 10 and 11) and, also, when the outer catheter 660 is navigating through thefemoral and iliac vessels. One specific embodiment of the sheath lumen654 has a length between approximately 30 and approximately 40 inches,in particular, 36 inches, an outer diameter of between approximately0.20 and approximately 0.25 inches, in particular 0.238 inches, and aninner diameter between approximately 0.18 and approximately 0.22 inches,in particular, 0.206 inches.

When the proximal handle 678 is moved towards its distal position, shownby the dashed lines in FIG. 11 , the nose cone assembly 630 and thesheath assembly 650 move towards a second position where the sheathassembly 650 is entirely out of the outer catheter 660 as shown in FIGS.20 and 21 . As can be seen most particularly in FIGS. 20 and 21 , as thenose cone assembly 630 and the sheath assembly 650 are emerging out ofthe outer catheter 660, they are traversing the curved portion 710 ofthe descending aorta. The tracking is accomplished visually by viewingradiopaque markers on various portions of the delivery system and/or thestent graft 1 with fluoroscopic measures. Such markers will be describedin further detail below. The delivery system can be made visible, forexample, by the nose cone 630 being radiopaque or containing radiopaquematerials.

It is noted that if the harder outer catheter 660 was to have been movedthrough the curved portion 710 of the aorta 700, there is a great riskof puncturing the aorta 700, and, particularly, a diseased portion 744of the proximal descending aorta 710 because the outer catheter 660 isnot as flexible as the inner sheath 652. But, because the inner sheath652 is so flexible, the nose cone assembly 630 and the sheath assembly650 can be extended easily into the curved portion 710 of the aorta 700with much less force on the handle than previously needed with prior artsystems while, at the same time, imparting harmless forces to theintraluminal surface of the curved aorta 710 due to the flexibility ofthe inner sheath 652.

At the second position shown in FIG. 21 , the user/physician, usingfluoroscopic tracking of radiopaque markers (e.g., marker 631) on anyportion of the nose cone or on the stent graft 1 and/or sheathassemblies 630, 650, for example, makes sure that the proximal end 112of the stent graft 1 is in the correct longitudinal position proximal tothe diseased portion 744 of the aorta 700. Because the entire insertedassembly 630, 650 in the aorta 700 is still rotationally connected tothe portion of the handle assembly 670 except for the distal handle 672(distal handle 672 is connected with the outer sheath 660 and rotatesindependently of the remainder of the handle assembly 670), thephysician can rotate the entire inserted assembly 630, 650 clockwise orcounterclockwise (indicated in FIG. 20 by arrow B) merely by rotatingthe proximal handle 678 in the desired direction. Such a feature isextremely advantageous because the non-rotation of the outer catheter660 while the inner sheath 652 is rotating eliminates stress on thefemoral and iliac arteries when the rotation of the inner sheath 652 isneeded and performed.

Accordingly, the stent graft 1 can be pre-aligned by the physician toplace the stent graft 1 in the optimal circumferential position. FIG. 23illustrates the longitudinal support member 40 not in the correctsuperior position and FIG. 24 illustrates the longitudinal supportmember 40 in the correct superior position. The optimal superior surfaceposition is, preferably, near the longest superior longitudinal linealong the circumference of the curved portion of the aorta as shown inFIGS. 23 and 24 . As set forth above, when the longitudinal supportmember 40 extends along the superior longitudinal line of the curvedaorta, the longitudinal support member 40 substantially eliminates anypossibility of forming a kink in the inferior radial curve of the stentgraft 1 during use and also allows transmission of longitudinal forcesexerted along the inside lumen of the stent graft 1 to the entirelongitudinal extent of the stent graft 1, thereby allowing the entireouter surface of the stent graft 1 to resist longitudinal migration.Because of the predefined curvature of the support member 40, thesupport member 40 cannot align exactly and entirely along the superiorlongitudinal line of the curved aorta. Accordingly, an optimal superiorsurface position of the support member 40 places as much of the centralportion of the support member 40 (between the two ends 47 thereof) aspossible close to the superior longitudinal line of the curved aorta. Aparticularly desirable implantation position has the superiorlongitudinal line of the curved aorta intersecting the proximal half ofthe support member 40—the proximal half being defined as that portion ofthe support member 40 located between the centerline 45 and the proximalsupport member loop 47. However, for adequate implantation purposes, thecenterline 45 of the support member 40 can be as much as seventycircumferential degrees away from either side of the superiorlongitudinal line of the curved aorta. Adequate implantation can meanthat the stent graft 1 is at least approximately aligned. Whenimplantation occurs with the stent graft 1 being less than seventydegrees, for example, less than forty degrees, away from either side ofthe superior longitudinal line of the curved aorta, then it issubstantially aligned.

In prior art stent grafts and stent graft delivery systems, the stentgraft is, typically, provided with symmetrically-shaped radiopaquemarkers along one longitudinal line and at least one othersymmetrically-shaped radiopaque marker disposed along anotherlongitudinal line on the opposite side (one-hundred eighty degrees(180°)) of the stent graft. Thus, using two-dimensional fluoroscopictechniques, the only way to determine if the stent graft is in thecorrect rotational position is by having the user/physician rotate thestent graft in both directions until it is determined that the firstlongitudinal line is superior and the other longitudinal line isanterior. Such a procedure requires more work by the physician and is,therefore, undesirable.

According to an exemplary embodiment of the invention illustrated inFIGS. 27 and 28 , unique radiopaque markers 232, 234 are positioned onthe stent graft 1 to assist the user/physician in correctly positioningthe longitudinal support member 40 in the correct aortic superiorsurface position with only one directional rotation, which correspondsto the minimal rotation needed to place the stent graft 1 in therotationally correct position.

Specifically, the stent graft 1 is provided with a pair of symmetricallyshaped but diametrically opposed markers 232, 234 indicating to theuser/physician which direction the stent graft 1 needs to be rotated toalign the longitudinal support member 40 to the superior longitudinalline of the curved aorta (with respect to anatomical position).Preferably, the markers 232, 234 are placed at the proximate end 12 ofthe graft sleeve 10 on opposite sides (one-hundred eighty degrees(180°)) of the graft sleeve 10.

The angular position of the markers 232, 234 on the graft sleeve 10 isdetermined by the position of the longitudinal support member 40. In anexemplary embodiment, the support member 40 is between the two markers232, 234. To explain such a position, if the marker 232 is at a 0 degreeposition on the graft sleeve 10 and the marker 234 is at a one-hundredeighty degree (180°) position, then the centerline 45 of the supportmember 40 is at a ninety degree position. However, an alternativeposition of the markers can place the marker 234 ninety degrees awayfrom the first degree 41 (see FIG. 1 ). Such a positioning is dependentsomewhat upon the way in which the implantation is to be viewed by theuser/physician and can be varied based on other factors. Thus, theposition can be rotated in any beneficial way.

Exemplary ancillary equipment in endovascular placement of the stentgraft 1 is a fluoroscope with a high-resolution image intensifiermounted on a freely angled C-arm. The C-arm can be portable, ceiling, orpedestal mounted. It is important that the C-arm have a complete rangeof motion to achieve AP to lateral projections without moving thepatient or contaminating the sterile field. Capabilities of the C-armshould include: Digital Subtraction Angiography, High-resolutionAngiography, and Roadmapping.

For introduction of the delivery system into the groin access arteries,the patient is, first, placed in a sterile field in a supine position.To determine the exact target area for placement of the stent graft 1,the C-arm is rotated to project the patient image into a left anterioroblique projection, which opens the radial curve of the thoracic aorticarch for optimal visualization without superimposition of structures.The degree of patient rotation will vary, but is usually 40 to 50degrees. At this point, the C-arm is placed over the patient with thecentral ray of the fluoroscopic beam exactly perpendicular to the targetarea. Such placement allows for the markers 232, 234 to be positionedfor correct placement of the stent graft 1. Failure to have the centralray of the fluoroscopic beam perpendicular to the target area can resultin parallax, leading to visual distortion to the patient anatomy due tothe divergence of the fluoroscopic x-ray beam, with a resultantmisplacement of the stent graft 1. An angiogram is performed and theproposed stent graft landing zones are marked on the visual monitor.Once marked, neither the patient, the patient table, nor thefluoroscopic C-arm can be moved, otherwise, the reference markers becomeinvalid. The stent graft 1 is, then, placed at the marked landing zones.

In an exemplary embodiment, the markers 232, 234 are hemispherical, inother words, they have the approximate shape of a “D”. This shape ischosen because it provides special, easy-to-read indicators thatinstantly direct the user/physician to the correct placement positionfor the longitudinal support member 40. FIG. 27 , for example,illustrates a plan view of the markers 232, 234 when they are placed inthe upper-most superior longitudinal line of the curved aorta. Thecorrect position is indicated clearly because the two hemispheres havethe flat diameters aligned on top of or immediately adjacent to oneanother such that a substantially complete circle is formed by the twohemispherically rounded portions of the markers 232, 234. This positionis also indicated in the perspective view of FIG. 28 .

Each of FIGS. 27 and 28 have been provided with examples where themarkers 232, 234 are not aligned and, therefore, the stent graft 1 isnot in the correct insertion position. For example, in FIG. 27 , twomarkers 232′, 234′ indicate a misaligned counter-clockwise-rotated stentgraft 1 when viewed from the plane 236 at the right end of the stentgraft 1 of FIG. 23 looking toward the left end thereof and down the axis11. Thus, to align the markers 232′, 234′ in the most efficient waypossible (the shortest rotation), the user/physician sees that thedistance between the two flat diameters is closer than the distancebetween the highest points of the hemispherical curves. Therefore, it isknown that the two flat diameters must be joined together by rotatingthe stent graft 1 clockwise.

FIG. 28 has also been provided with two markers 232″, 234″ indicating amisaligned clockwise-rotated stent graft 1 when viewed from the plane236 at the right end of the stent graft 1 of FIG. 27 looking toward theleft end thereof and down the axis 11. Thus, to align the markers 232″,234″ in the most efficient way possible (the shortest rotation), theuser/physician sees that the distance between the highest points of thehemispherical curves is smaller than the distance between the two flatdiameters. Therefore, it is known that the two flat diameters must bejoined together by rotating the stent graft 1 in the direction that thehighest points of the hemispherical curves point; in other words, thestent graft 1 must be rotated counter-clockwise.

A significant advantage provided by the diametrically opposed symmetricmarkers 232, 234 is that they can be used for migration diagnosisthroughout the remaining life of a patient after the stent graft 1 hasbeen placed inside the patient's body. If fluoroscopic or radiographictechniques are used any time after the stent graft 1 is inserted in thepatient's body, and if the stent graft 1 is viewed from the same angleas it was viewed when placed therein, then the markers' 232, 234relative positions observed should give the examining individual a veryclear and instantaneous determination as to whether or not the stentgraft 1 has migrated in a rotational manner.

The hemispherical shape of the markers 232, 234 are only provided as anexample shape. The markers 232, 234 can be any shape that allows auser/physician to distinguish alignment and direction of rotation foralignment. For example, the markers 232, 234 can be triangular, inparticular, an isosceles triangle having the single side be visiblylonger or shorter than the two equal sides.

As set forth above, alignment to the optimal implantation position isdependent upon the skill of the physician(s) performing theimplantation. The present invention improves upon the embodiments havinglongitudinal and rotational radiopaque markers 232, 234 andsubstantially eliminates the need for rotational markers. Specifically,it is noted that the guidewire 610 travels through a curve through theaortic arch towards the heart 720. It is, therefore, desirable topre-shape the delivery system to match the aorta of the patient.

The guidewire lumen 620 is formed from a metal, preferably, stainlesssteel. Thus, the guidewire lumen 620 can be deformed plastically intoany given shape. In contrast, the apex release lumen 640 is formed froma polymer, which tends to retain its original shape and cannotplastically deform without an external force, e.g., the use of heat.Therefore, to effect the pre-shaping of the delivery assembly 600, theguidewire lumen 620, as shown in FIG. 64 , is pre-shaped with a curve ata distal-most area 622 of the lumen 620. The pre-shape can bedetermined, for example, using the fluoroscopic pre-operative techniquesdescribed above, in which the guidewire lumen 620 can be customized tothe individual patient's aortic shape. Alternatively, the guidewirelumen 620 can be pre-shaped in a standard manner that is intended to fitan average patient. Another alternative is to provide a kit that can beused to pre-shape the guidewire lumen 620 in a way that is somewhattailored to the patient, for example, by providing a set of deliverysystems 600 or a set of different guidewire lumens 620 that havedifferent radii of curvature.

With the pre-curved guidewire lumen 620, when the nose cone 632 andinner sheath 652 exit the outer catheter 660 and begin to travel alongthe curved guidewire 610, the natural tendency of the pre-curvedguidewire lumen 620 will be to move in a way that will best align thetwo curves to one another (see FIGS. 20 and 21 ). The primary factorpreventing the guidewire lumen 620 from rotating itself to cause such analignment is the torque generated by rotating the guidewire lumen 620around the guidewire 610. The friction between the aorta and the devicealso resists rotational motion. The delivery system 600, however, isconfigured naturally to minimize such torque. As set forth above withrespect to FIGS. 15 to 17 , the guidewire lumen 620 freely rotateswithin the apex release lumen 640 and is only connected to the apexrelease lumen 640 at the proximal-most area of both lumen 620, 640.While the inner sheath 652 advances through the aortic arch, the twolumen 620, 640 are rotationally connected only at the apex releaseassembly 690. This means that rotation of the guidewire lumen 620 aboutthe guidewire 610 and within the apex release lumen 640 occurs along theentire length of the guidewire lumen 620. Because the metallic guidewirelumen 620 is relatively rotationally elastic along its length, rotationof the distal-most portion (near the nose cone assembly 630) withrespect to the proximal-most portion (near the apex release assembly690) requires very little force. In other words, the torque resistingrotation of the distal-most portion to conform to the curve of theguidewire 610 is negligible. Specifically, the torque is so low that theforce resisting the alignment of the guidewire lumen 620 to theguidewire 610 causes little, negligible, or no damage to the inside ofthe aorta, especially to a dissecting inner wall of a diseased aorta.

Due to the configuration of the delivery system 600 of the presentinvention, when the guidewire lumen 620 is extended from the outercatheter 660 (along with the apex release lumen 640, the stent graft 1,the inner sheath 652 as shown in FIGS. 20 and 21 , for example), thepre-shape of the guidewire lumen 620 causes automatic and naturalrotation of the entire distal assembly—including the stent graft 1—alongits longitudinal axis. This means that the length and connectivity ofthe guidewire lumen 620, and the material from of which the guidewirelumen 620 is made, allow the entire distal assembly (1, 620, 630, 640,650) to naturally rotate and align the pre-curved guidewire lumen 620with the curve of the guidewire 610—this is true even if the guidewirelumen 620 is inserted into the aorta entirely opposite the curve of theaorta (one-hundred eighty degrees (180°)). In all circumstances, thecurved guidewire lumen 620 will cause rotation of the stent graft 1 intoan optimal implantation position, that is, aligning the desired portionof the support member 40 within ±70 degrees of the superior longitudinalline of the curved aorta. Further, the torque forces acting againstrotation of the guidewire lumen 620 will not be too high to cause damageto the aorta while carrying out the rotation.

The self-aligning feature of the invention begins with a strategicloading of the stent graft 1 in the inner sleeve 652. To describe theplacement of the supporting member 40 of the stent graft 1 relative tothe curve 622 of the guidewire lumen 620, an X-Y coordinate curve planeis defined and shown in FIG. 64 . In particular, the guidewire lumen 620is curved and that curve 622 defines the curve plane 624.

To insure optimal implantation, when loading the stent graft 1 into theinner sheath 652, a desired point on the supporting member 40 betweenthe centerline 45 of the stent graft 1 and the proximal support memberloop 47 is aligned to intersect the curve plane 624. An exemplary, butnot required, location of the desired point on the supporting member 40is located forty-five (45) degrees around the circumference of the stentgraft 1 shown in FIG. 1 beginning from the first degree 41 in line withthe proximal support member loop 47. When the stent graft 1 is loaded inan exemplary orientation, it is ready for insertion into the innersleeve 652. During the loading process, the stent graft 1 and theguidewire lumen 620 are held constant rotationally. After such loading,the inner sleeve 652 is retracted into the outer catheter 660 and thedelivery system 600 is ready for purging with saline and use with apatient.

FIGS. 65 to 67 illustrate self-alignment of the distal assembly 620,630, 640, 650 after it is pushed out from the distal end of the outercatheter 660 (see FIGS. 20 and 21 ). FIG. 65 shows an aorta 700 and thedistal assembly after it has traversed the iliac arteries 802 and entersthe descending thoracic portion 804 of the aorta. The nose cone assembly630 is positioned just before the aortic arch 806 and the stent graft 1is contained within the inner sheath 652. A reference line 820 is placedon the stent graft 1 at a longitudinal line of the stent graft 1 that isintended to align with the superior longitudinal line 808 (indicatedwith dashes) of the aortic arch 806. In FIG. 65 , the reference line 820also lies on the curved plane 624 defined by the pre-curved guidewirelumen 620. As can be clearly seen from FIG. 65 , the reference line 820is positioned almost on or on the inferior longitudinal line of thecurved aorta—thus, the stent graft 1 is one-hundred eighty degrees(180°) out of alignment. FIG. 66 shows the nose cone assembly 630 fullyin the aortic arch 806 and the inner sleeve 652 at the entrance of theaortic arch 806. With the self-aligning configuration of the pre-curvedguidewire lumen 620, movement of the distal assembly from the positionshown in FIG. 65 to the position shown in FIG. 66 causes a rotation ofthe reference line 820 almost ninety degrees (90°) clockwise (withrespect to a view looking upward within the descending aorta) towardsthe superior longitudinal line 808. In FIG. 67 , the nose cone assembly630 has reached, approximately, the left subclavian artery 810.Rotational movement of the distal assembly is, now, complete, with thereference line 820 almost aligned with the superior longitudinal line808 of the aortic arch 806. From the views of FIGS. 65 to 67 , alsoshown is the fact that the pre-curved guidewire lumen 620 has not causedany portion of the inner sleeve 652 to push against the inner surface ofthe aortic arch 806 with force—force that might exacerbate an aorticdissection.

It is noted that the guidewire lumen 620 need not be rotationallyfixedly connected to the apex release lumen 640 when the apex releaseassembly 690 is in the locked position shown in FIGS. 15 and 16 .Instead, a non-illustrated, freely rotatable coupling can be interposedanywhere along the guidewire lumen 620 (but, preferably, closer to theapex release assembly 690). This coupling would have a proximal portionrotationally fixedly connected to the to the apex release lumen 640 whenthe apex release assembly 690 is in the locked position shown in FIGS.15 and 16 and a freely-rotatable distal portion that is fixedlyconnected to all of the guidewire lumen 620 disposed distal thereto.Thus, the guidewire lumen 620 near the sheath assembly 650 will alwaysbe freely rotatable and, thereby, allow easy and torque-free rotation ofthe guidewire lumen 620 about the guidewire 610.

It is also noted that the pre-curved section 622 of the guidewire lumenneed not be made at the manufacturer. As shown in FIG. 69 , a curvingdevice can be provided with the delivery system 600 to allow thephysician performing the implantation procedure to tailor-fit the curve622 to the actual curve of the vessel in which the stent graft 1 is tobe implanted. Because different patients can have different aortic archcurves, a plurality of these curving devices can be provided with thedelivery system 600, each of the curving devices having a differentcurved shape. Each device can also have two sides with each side havinga different curved shape, thus, reducing the number of devices if alarge number of curves are required. Further, the curving devices canall be rotationally connected on a common axle or spindle for each oftransport, storage, and use.

For tailoring the curve to the patient's curved vessel, the physiciancan, for example, fluoroscopically view the vessel (e.g., aortic arch)and determine therefrom the needed curve by, for example, holding up thecurving device to the display. Any kind of curving device can be used toimpart a bend to the guidewire lumen 620 when the guidewire lumen 620 isbent around the circumference.

Because of the predefined curvature of the support member 40, thesupport member 40 cannot align exactly and entirely along the superiorlongitudinal line of the curved aorta. Accordingly, an optimal superiorsurface position of the support member 40 places as much of the centralportion of the support member 40 (between the two ends 47 thereof) aspossible close to the superior longitudinal line 808 of the curvedaorta. A particularly desirable implantation position has the superiorlongitudinal line 808 of the curved aorta intersecting the proximal halfof the support member 40—the proximal half being defined as that portionof the support member 40 located between the centerline 45 and theproximal support member loop 47. However, for adequate implantationpurposes, the centerline 45 of the support member 40 can be as much asseventy circumferential degrees away from either side of the superiorlongitudinal line of the curved aorta.

When the stent graft 1 is in place both longitudinally andcircumferentially (FIG. 21 ), the stent graft 1 is ready to be removedfrom the inner sheath 652 and implanted in the vessel 700. Becauserelative movement of the stent graft 1 with respect to the vessel is nolonger desired, the inner sheath 652 needs to be retracted while thestent graft 1 remains in place, i.e., no longitudinal or circumferentialmovement. Such immovability of the stent graft 1 is insured by, first,the apex capture device 634 of the nose cone assembly 630 holding thefront of the stent graft 1 by its bare stent 30 (see FIGS. 13, 22, and23 ) and, second, by unlocking the locking knob 676/placing the lockingring/knob in the D position—which allows the sheath lumen 654 to moveindependently from the guidewire lumen 620, apex release lumen 640, andgraft push lumen 642. The apex capture device 634, as shown in FIGS. 13,14, 30 and 311 (and as will be described in more detail below), isholding each individual distal apex 32 of the bare stent 30 in a securemanner—both rotationally and longitudinally.

The nose cone assembly 630, along with the apex capture device 634, issecurely attached to the guidewire lumen 620 (and the apex release lumen640 at least until apex release occurs). The inner sheath 652 issecurely attached to a sheath lumen 654, which is coaxially disposedaround the guidewire lumen 620 and fixedly attached to the proximalhandle 678. The stent graft 1 is also supported at its distal end by thegraft push lumen 642 and the distal sleeve 644 or, the taper 653 of theinner sheath 652. (The entire coaxial relationship of the various lumens610, 620, 640, 642, 654, and 660 is illustrated for exemplary purposesonly in FIG. 25 , and a portion of which can also be seen in theexploded view of the handle assembly in FIG. 50 ) Therefore, when theproximal handle 678 is moved proximally with the locking knob 676 in thedeployment position D, the sheath lumen 654 moves proximally as shown inFIGS. 13, 22, and 23 , taking the sheath 652 proximally along with itwhile the guidewire lumen 620, the apex release lumen 640, the graftpush lumen 642, and the distal sleeve 644 remain substantiallymotionless and, therefore, the stent graft 1 remains both rotationallyand longitudinally steady.

The stent graft 1 is, now, ready to be finally affixed to the aorta 700.To perform the implantation, the bare stent 30 must be released from theapex capture device 634. As will be described in more detail below, theapex capture device 634 shown in FIGS. 13, 14, and 29 to 32 , holds theproximal apices 32 of the bare stent 30 between the distal apex head 636and the proximal apex body 638. The distal apex head 636 is fixedlyconnected to the guidewire lumen 620. The proximal apex body 638,however, is fixedly connected to the apex release lumen 640, which iscoaxial with both the guidewire lumen 620 and the sheath lumen 654 anddisposed therebetween, as illustrated diagrammatically in FIG. 25 . (Aswill be described in more detail below, the graft push lumen 642 is alsofixedly connected to the apex release lumen 640.) Therefore, relativemovement of the apex release lumen 640 and the guidewire lumen 620separates the distal apex head 636 and a proximal apex body 638 from oneanother.

To cause such relative movement, the apex release assembly 690 has, inan exemplary embodiment, three parts, a distal release part 692, aproximal release part 694, and an intermediate part 696 (which is shownin the form of a clip in FIGS. 16 and 26 ). To insure that the distalapex head 636 and the proximal apex body 638 always remain fixed withrespect to one another until the bare stent 30 is ready to be released,the proximal release part 694 is formed with a distal surface 695, thedistal release part 692 is formed with a proximal surface 693, and theintermediate part 696 has proximal and distal surfaces corresponding tothe surfaces 695, 693 such that, when the intermediate part 696 isinserted removably between the distal surface 695 and the proximalsurface 693, the intermediate part 696 fastens the distal release part692 and the proximal release part 694 with respect to one another in aform-locking connection. A form-locking connection is one that connectstwo elements together due to the shape of the elements themselves, asopposed to a force-locking connection, which locks the elements togetherby force external to the elements. Specifically, as shown in FIG. 26 ,the clip 696 surrounds a distal plunger 699 of the proximal release part694 that is inserted slidably within a hollow 698 of the distal releasepart 692. The plunger 699 of the proximal release part 694 can slidewithin the hollow 698, but a stop 697 inside the hollow 698 prevents thedistal plunger 699 from withdrawing from the hollow 698 more than thelongitudinal span of the clip 696.

To allow relative movement between the distal apex head 636 and theproximal apex body 638, the intermediate part 696 is removed easily withone hand and, as shown from the position in FIG. 16 to the position inFIG. 17 , the distal release part 692 and the proximal release part 694are moved axially towards one another (preferably, the former is movedtowards the latter). Such movement separates the distal apex head 636and the proximal apex body 638 as shown in FIG. 14 . Accordingly, thedistal apices 32 of the bare stent 30 are free to expand to theirnatural position in which the bare stent 30 is released against thevessel 700.

Of course, the apex release assembly 690 can be formed with any kind ofconnector that moves the apex release lumen 640 and the guidewire lumen620 relative to one another. In an exemplary alternative embodiment, forexample, the intermediate part 696 can be a selectable lever that isfixedly connected to either one of the distal release part 692 or theproximal release part 694 and has a length equal to the width of theclip 696 shown in FIG. 26 . Thus, when engaged by pivoting the leverbetween the distal release part 692 and the proximal release part 694,for example, the parts 692, 694 cannot move with respect to one anotherand, when disengaged by pivoting the lever out from between the parts692, 694, the distal release part 692 and the proximal release part 694are free to move towards one another.

The apex capture device 634 is unique to the present invention in thatit incorporates features that allow the longitudinal forces subjected onthe stent graft 1 to be fully supported, through the bare stent 30, byboth the guidewire lumen 620 and apex release lumen 640. Support occursby providing the distal apex head 636 with a distal surface 639—whichsurface 639 supports the proximal apices 32 of the bare stent 30 (shownin the enlarged perspective view of the distal apex head 636 in FIG. 29). When captured, each proximal apex 32 of the bare stent 30 separatelyrests on a distal surface 639, as more clearly shown in FIGS. 30 and 31. The proximal spokes of the distal apex head 636 slide within thefingers of the proximal apex body 638 as these parts moves towards oneanother. A slight space, therefore, exists between the fingers and theouter circumferential surfaces of the spokes. To insure that the barestent 30 does not enter this space (which would prevent a proper releaseof the bare stent 30 from the apex capture device 634, a radialthickness of the space must be less than the diameter of the wire makingup the bare stent 30. Preferably, the space is no greater than half adiameter of the wire.

Having the distal surface 639 be the load-bearing surface of theproximal apices 32 ensures expansion of each and every one of the distalapices 32 from the apex release assembly 690. The proximal surface 641of the distal apex head 636 (see FIG. 30 ) meets with the interiorsurfaces of the proximal apex body 638 to help carry the apex loadbecause the apices of the bare stent 30 are captured therebetween whenthe apex capture device 634 is closed. Complete capture of the barestent 30, therefore, fully transmits any longitudinal forces acting onthe bare stent 30 to both the guidewire lumen 620 and apex release lumen640, making the assembly much stronger. Such capture can be clearly seenin the cut-away view of the proximal apex body 638 in FIG. 31 . Forrelease of the apices 32 of the bare stent 30, the proximal apex body638 moves leftward with respect to FIGS. 30 to 33 (compare FIGS. 30 and31 with FIG. 32 ). Because friction exists between the apices 32 and the“teeth” of the proximal apex body 638 when the apices 32 are captured,the apices 32 will also try to move to the left along with the proximalapex body 638 and, if allowed to do so, possibly would never clear the“teeth” to allow each apex 32 to expand. However, as the proximal apexbody 638 disengages (moves in the direction of arrow C in FIG. 31 ),direct contact with the distal surface 639 entirely prevents the apices32 from sliding in the direction of arrow C along with the proximal apexbody 638 to ensure automatic release of every captured apex 32 of thebare stent 30. Because the proximal apex body 638 continues to move inthe direction of arrow C, eventually the “teeth” will clear theirrespective capture of the apices 32 and the bare stent 30 will expandentirely. The release position of the distal apex head 636 and theproximal apex body 638 is shown in FIGS. 14 and 32 , and corresponds tothe position of the apex release assembly 690 in FIG. 17 . As can beseen, tapers on the distal outer surfaces of the proximal apex body 638further assist in the prevention of catching the proximal apices 32 ofthe bare stent 30 on any part of the apex capture device 634. In thisconfiguration, the distal surfaces 639 bear all the load upon the barestent 30 and the fingers of the proximal apex body 638.

Simply put, the apex capture device 634 provides support for load placedon the stent graft 1 during advancement A of the inner sheath 652 andduring withdrawal of the inner sheath 652 (i.e., during deployment D).Such a configuration benefits the apposition of the bare stent 30 byreleasing the bare stent 30 after the entire graft sleeve 10 has beendeployed, thus reducing the potential for vessel perforation at thepoint of initial deployment.

When the stent graft 1 is entirely free from the inner sheath 652 asshown in FIG. 24 , the proximal handle 678 is, then, substantially at ornear the third position (deployment position) shown in FIG. 10 .

The stent graft 1 is, now, securely placed within the vessel 700 and theentire portion 630, 650, 660 of the assembly 600 may be removed from thepatient.

FIGS. 70 and 71 illustrate alternative configurations of the stent graft1 of FIG. 1 . The stent graft 1000 of FIG. 70 is similar to the stentgraft 1 of FIG. 1 . The stent graft 1000 has a graft 1010 and a numberof stents 1020. The stents 1020 are attached either to the exterior orinterior surfaces of the graft sleeve 1010. Preferably, the stents 1020are sewn to the graft 1010. The stent graft 1000 shown in FIG. 70 hasbeen discussed above with respect to FIG. 1 , for example, and,therefore, the discussion relevant to features already discussed willnot be repeated for the sake of brevity.

FIG. 70 shows an exemplary embodiment of the curved ends 1047 of theconnecting rod 1040. In particular, the rod 1040 forms a loop (whether,polygonal, ovular, or circular) and has an end portion 1048 thatcontinues back parallel and next to the rod 1040 for a short distance.This end portion 1048, along with the adjacent portion of the rod 1040allows, for example, connective stitching to cover two lengths of therod 1040 and better secures the end portion 1048 to the graft sleeve1010. In such configuration, there is limited or even no chance of asharp end of the rod 1040 to be exposed to harm the graft sleeve 1010 orthe vessel wall in which the stent graft 1000 is placed.

An alternative embodiment of the stent graft 1000 is shown as stentgraft 1100 in FIG. 71 . This stent graft 1100 contains a graft sleeve1110 that completely covers the bare stent 30 shown in FIGS. 1 and 70and is hereinafter referred to with respect to FIGS. 71 to 78 as aclasping stent 1130. As shown particularly well in FIGS. 72 and 74 , theclasping stent 1130 is entirely covered by the graft 1110 but is notattached to the material of the graft 1110 along its entirety.

At least some of the proximal apices 1132, preferably, at least three orfour, are left unconnected to permit a releasable connection with thefingers of the proximal apex body 638 when the fingers are extendedthrough the apex openings 1134. Of course, in certain applications, itmay be beneficial to only leave one apex 1132 unconnected. Theunconnected portion of each the apices 1132 has a minimal longitudinallength of about 10 percent of the longitudinal length of the stent and amaximum longitudinal length of up to approximately 90 percent of thelength of the stent. Preferably, the longitudinal length of theunconnected portion is between approximately 30 to 40 percent as shownin FIGS. 72 and 74 , which show the clasping stent 1130 sewn to theinterior of the graft 1110. For ease of comparison, FIG. 73 illustratingthe proximal end of the stent graft of FIGS. 1 and 70 is included nextto FIG. 74 . The unconnected portions of apices 1132 need not have thesame longitudinal lengths. Depending on the application, one or some ofthe unconnected portions of apices 1132 can have a longitudinal lengthdifferent from other ones of the unconnected portions of apices 1132.FIG. 75, for example, illustrates an embodiment near the maximumlongitudinal length of the unconnected portion of the clasping stent1130.

FIGS. 76 and 77 illustrate a proximal end of the stent graft 1100 ofFIG. 71 partially deployed from the flexible inner sheath 652. As can beseen in FIG. 76 , the entire capturing assemblies of the apex capturedevice 634 reside inside the stent graft 1100 when the apices arecaptured. Only the distal-most portion of the distal apex head 636extends out from the interior of the stent graft 1100. With regard tothe view of FIG. 77 , it can be seen that only a few of the apices 1132of the clasping stent 1130 are actually held by the apex capture device634.

It is noted at this point that implantation of the stent graft 1, 1000,1100 of the present invention occurs while blood is flowing from theheart of the patient. Accordingly, the stent graft 1100 cannot occludethe vessel in which it is to be implanted and, in order to do so, theremust exist a lumen for passing blood throughout the time after the stentgraft 1100 has partially or fully expanded within the vessel. If all ofthe apices 1132 of the clasping stent 1130 were held within the apexcapture device 634, then there is a possibility of occluding the vesselif the unattached portion of the apices 1132 are too short to providesuch a lumen. To avoid this condition, if only some apices 1132 of theclasping stent 1130 are captured, as illustrated in FIG. 77 , then asufficiently large lumen exists to allow blood flow through the vesselin which the stent graft is to be implanted. Alternatively, if a largepercentage of the apices 1132 are left unconnected, as shown, forexample, in FIG. 75 , then all of the apices 1132 can be releasably heldby the apex capture device 634 while the graft sleeve 1110 remainsentirely open to allow blood flow through the stent graft 1100 duringthe stent graft 1100 implantation process.

There exists a drawback to placing the clasping stent 1130 as theproximal stent of the stent graft 1100 because material of the graft1110 is proximal of the clasping stent 1130. If unsupported, thismaterial could move disadvantageously toward the interior of the stentgraft 1100 after implantation and decrease or occlude blood flow. Toprevent such movement, the stent graft 1100 also includes a crown stent1140. Like the clasping stent 1130, the crown stent 1140 is shown inFIGS. 71, 72, 74 to 76, and 78 as being attached to the inside of thegraft 1120 and, in this exemplary embodiment, is sewn to the material ofthe graft using the same polyester suture as the other stents. Ofcourse, the crown stent 1140 can be attached to the exterior of thegraft 1010. In such a configuration, the crown stent 1140 augments therigidity of the material of the graft 1120 to reduce enfolding thereofat the proximal end of the stent graft 1100.

Alternatively and/or additionally, a non-illustrated distal crown stentcan be attached to the inside or outside of the graft 1120 at theopposite distal end of the stent graft 1100. In such a configuration,this distal crown stent 1140 augments the rigidity of the material atthe distal end of the graft 1120 to reduce enfolding thereof.

The material of the graft 1120 can extend and bridge the entire distancebetween two proximal crown apices 1122. It is noted, however, that,alternatively or additionally, the material of the graft 1120 may bepartially cut out between crown apices 1122 of the crown stent 1140 todefine a plurality of a radially distensible flange portions 1124 at theproximal end of the stent graft 1100, as shown in FIG. 74 .

There are various advantages provided by the stent graft 1100 over theprior art. First, the clasping and crown stents 1130, 1140 improve theapposition of the material of the graft to the intima of the vessel inwhich the stent graft 1100 is placed, in particular, in the aorta.Second, by better aligning the proximal portion of the stent graft 1110in the lumen of the arch, the clasping and crown stents 1130, 1140provide an improved blood-tight closure of the proximal end of the stentgraft 1110 so that blood does not pass between the intima of thevasculature and the outer surface of the stent graft 1110.

As set forth above, if the apex capture device 634 captures less thanall of the apices of the clasping stent 1130. The resulting openingsallow blood flow during implantation. It is illustrated particularlywell in FIGS. 1, 13, 14, and 70 that the material of the graft 10 ofstent graft 1, 1000 begins only distal of the center of the bare stent32. In comparison, as shown in FIGS. 71 and 73 , the material of thegraft 1120 begins well proximal of the proximal-most apices of theclasping stent 1130. Thus, this embodiment allows the material of thegraft 1120 to extend much further into a vessel (i.e., further into thecurved arch of the aorta). Therefore, a physician can repair a vesselfurther upstream in the aorta than the embodiment of the stent graft 1,1000 of FIGS. 1 and 70 .

In the prosthesis embodiment of FIGS. 1 and 70 , there is direct contactbetween the metal of the bare stent 32 and the intima of the bloodvessel. In contrast thereto, the configuration of the stent graft 1100with the clasping stent 1130 places material of the graft 1120 betweenthe metal of the clasping stent 1130 and the intima. Such aconfiguration provides a more atraumatic connection between the vesseland the proximal end of the stent graft 1100 than the configuration ofFIGS. 1 and 70 . This advantage is especially important for treatingdissections—where the intima is in a weakened condition.

FIG. 63 illustrates interaction between the catheter 660, the innersheath 652, and the nose cone assembly 630 (including the nose cone 632,the distal apex head 636, and the proximal apex body 638). In thisillustration, first, the catheter 660 is in a proximal position thatdoes not cover the inner sheath 652 in any way. For example, thisposition of the catheter 660 occurs when the inner sheath 652 hasextended out of the catheter 660 as shown in FIGS. 20 and 21 .

Next, the inner sheath 652 is clearly shown in its expanded state(caused by the non-illustrated prosthesis disposed therein and expandingoutward). The distal-most end of the inner sheath 652 is disposedbetween the distal apex head 636 and the nose cone 632. In such anorientation, the inner sheath 652 is in the position that occurs duringextension out of the catheter 660 as shown for example, in FIGS. 20 and21 . Because the nose cone 632 screws onto the distal end of the distalapex head 636, the distal-most end of the inner sheath 652 is releasablycaptured between the two parts 632, 636 until it is removed. Retractionof the sheath lumen 654 proximally pulls the distal-most captured end ofthe inner sheath 652 out from the capturing interface.

Finally, the proximal apex body 638 is in a retracted position proximalof the distal apex head 636. This orientation is for illustrativepurposes only to show the interaction of the distal apex head 636 andthe proximal apex body 638 because the separation would not occur in useuntil, as set forth above, the inner sheath 652 is fully retracted fromover the stent graft 1 and the proximal apices 32 of the stent 30 havebeen released as shown in FIG. 14 .

FIG. 80 is a cross-section through the catheter 660, the fingers of theproximal apex body 638, the distal apex body 636, the apex release lumen640, and the guidewire 620. FIG. 81 is a cross-section of the distal endof the delivery system along the longitudinal axis of the deliverysystem. These two figures illustrate the space 662 that exists betweenthe catheter 660 and both of the proximal apex body 638 and the distalapex body 636 to make room for the inner sheath 652 to surround theparts 636, 638 and pass between the nose cone 632 and the distal apexhead 636 and enter the pass 664 that allows the inner sheath 652 to bereleasably held there as shown in FIG. 63 until it is desired to removethe inner sheath 652 therefrom.

FIG. 82 shows a distal end of the delivery system according to theinvention in the orientation of FIGS. 20 and 21 , for example. The innersheath 652 is curved and has an alternative embodiment of a D-shapedmarker 234 thereon. In contrast to the configuration of two markers 234on the stent graft 1 as shown in FIGS. 27 and 28 , there is only onemarker 234 on the inner sheath 652. As illustrated in the orientationsof FIGS. 83, 84, and 85 , the marker 234 allows the user to see how theinner sheath 652 should be oriented prior to implantation.

FIGS. 86, 87, 88, and 89 illustrate an alternative embodiment of thefront handle 672 that is rotatably attached to the handle 674 androtatably fixed to the catheter 660.

FIGS. 90 to 119 depict another exemplary embodiment of various featuresof the delivery assembly 600.

FIG. 90 shows the entire delivery assembly 600 with a portion of nosecone assembly 630 removed to reveal the distal apex head 636.

On the proximal end of the delivery assembly 600, the enlarged view ofFIG. 91 depicts an alternative embodiment of the apex release assembly690. In FIG. 91 , a proximal pusher support tube 645 surrounds twocoaxial lumens, the guidewire lumen 620 and the apex release lumen 640.The proximal pusher support tube 645 is longitudinally fixed to theproximal end of the graft push lumen 642 and has substantially the samediameter as the graft push lumen 642. Because the proximal pushersupport tube 645 is used for pushing/pulling the combination lumen 642,645, and due to the fact that the proximal pusher support tube 645 onlyresides within the handle body or proximal thereof, the proximal pushersupport tube 645 can be made of a relatively stiff material, such asstainless steel, for example. In contrast, the graft push lumen 642needs to flex and bend when extending out of the outer catheter 660 andinto vasculature. Thus, the graft push lumen 642 is made from arelatively flexible material, such as a plastic. In FIG. 91 , theproximal portion of the proximal pusher support tube 645 is cut away toreveal the features therein, including the guidewire lumen 620 and theapex release lumen 640.

The apex release lumen 640 is axially fixed to the proximal apex body638. The guidewire lumen 620, on the other hand, is axially fixed to thedistal apex head 636. Thus, distal movement of the apex release lumen640 with respect to the guidewire lumen 620 separates the tines of theproximal apex body 638 extending over the spokes of the distal apex head636. To effect this relative movement, proximal and distal crimpingdevices 621 and 641 are respectively attached to the guidewire 620 andthe apex release lumen 640. The distal release part 692 is connected,through a non-illustrated set screw, to the distal crimping device 641.The proximal release part 694 is connected, also through anon-illustrated set screw, to the proximal crimping device 621. Finally,a proximal luer connector 800 is connected to the proximal-most end ofthe proximal pusher support tube 645 so that all of the lumen 620, 640,645 can be filled and/or drained with a liquid, such as saline.

FIG. 92 is an enlarged view of the alternative embodiment of the lockingknob 582 first shown in FIGS. 50 and 51 . To better explain the featuresof FIG. 92 , reference is made to the separated clasp sleeve 614 of FIG.93 , which was first depicted in FIGS. 50, 53, and 59 to 62 . This claspsleeve 614 is longitudinally fixedly and rotationally freely connectedto the handle body 674 through the setscrew 584 that protrudes into theslot 675 of the handle body 674. The setscrew 584 is screwed into butnot through the proximal end of the clasp sleeve as shown in FIG. 93 ,for example. This setscrew 584 protrudes into the slot 675 in the handlebody 674. When so connected, the clasp sleeve 614 cannot movelongitudinally with respect to the handle body 674 but can rotationallymove along the arc defined by the length of the slot 675. The setscrew584 protrudes from the outer circumference of the handle body 674because it enters into the longitudinal slot 583 in the locking knob582. Thus, the setscrew 584 also controls the longitudinal movementdistance of the locking knob 582. When the knob 582 is at rest, thesetscrew 584 resides in the distal end of the slot 583 because of thebias caused by spring 607 (see FIG. 94 ).

The second setscrew 592 (also referred to as a position pin) starts fromthe handle body 674 but does not extend inside the handle body 674. Thesetscrew 592 does, however, protrude out from the handle body 674 andinto the three-position slot 587 of the locking knob 582. Thus, thesetscrew 592 controls the rotation of the knob 582 within the threepositions.

The third setscrew 585 is screwed through a threaded hole in the handlebody 674 and into a co-axial threaded hole 6021 of the clasp body 602until the setscrew 585 is even with the exterior surface of the handlebody 674. Thus, the setscrew 585 does not protrude from the outercircumference of the handle body 674.

The proximal clasp assembly 604 was first illustrated in FIG. 52 . InFIG. 94 , the proximal clasp assembly 604 is illustrated with differentdetail. The clasp body 602 has a distal interior cavity 6023 shaped toreceive therein the distal clasp body spring 606, which is a torsionspring in this exemplary embodiment. The locking washer 608 is connectedto the distal end of the clasp body 602 by a non-illustrated setscrewthat, for example, runs through the bore illustrated at the 12 o'clockposition on the locking washer 608 in FIG. 94 . To keep the clasp bodyassembly pressed into the clasp sleeve 614, as shown in FIGS. 101 and102 for example, a distal spring washer 605 and a proximal compressionspring 607 are inserted into a proximal interior cavity 6024. Placementof the locking knob 676 onto the handle body 674, as shown in FIG. 92for example, compresses the compression spring 607 between the lockingknob 676 and the proximal surface of the spring washer 605 residinginside the proximal interior cavity 6023 of the clasp body 602. Thiscompression forces the knob 676 proximally to keep the spring 592 insidethe three-position slot 675. The spring washer 605 is present to preventthe spring 607 from binding when the locking knob 676 is rotated betweenthe three rotational positions. The smooth surface of the washer 605does not catch the distal end of the compression spring 607 when thespring 607 rotates.

The rotator assembly includes the pusher clasp rotator 292, the pusherclasp spring 298, and the rotator body 294. These parts are firstdepicted in FIGS. 34 to 43 and 47 to 48 and are next depicted in FIGS.95 and 96 . In FIG. 95 , the rotator assembly is illustrated in anexploded, unassembled state and FIG. 96 shows the assembly in anassembled state. When assembled, the two protruding ends of the pusherclasp spring 298 are respectively inserted into the longitudinal slots2942 and 2922 of each of the rotator body 294 and the pusher clasprotator 292. Because the distal end of the rotator body 294 is smallerin diameter than the cavity of the pusher clasp rotator 292, the end ofthe spring that fits inside the slot 2922 must be longer than the end ofthe spring 298 that fits inside the slot 2942 of the rotator body 294.

The rotator body 294 is secured inside the pusher clasp rotator 292 bytwo dowels 2926 that are press fit through a first orifice in the clasprotator 292 after the rotator body 294 is inside the clasp rotator 292.These dowels 2926, then, pass through a circumferential groove 2944substantially without touching the walls of the groove 2944 and, then,through a second orifice in the clasp rotator 292 directly opposite thefirst orifice. In such a configuration, the rotator body 294 islongitudinally fixed but rotationally free inside the clasp rotator 292.The first and second orifices and the groove 2944 are clearly shown inFIG. 113 (with the dowels 2926 removed for clarity).

FIGS. 44 to 48 illustrated the pusher clasp body 296 and itsrelationship with the sheath lumen 654. FIGS. 97 and 98 furtherillustrate two views of the pusher clasp body 296 and its distalprojection 297. The proximal end of the sheath lumen 654 passes throughthe crimp ring 295 and over the distal projection 297. Then, to securethe sheath lumen 654 to the pusher clasp body 296, the crimp ring 295 iscompressed/crimped. Such a connection both longitudinally androtationally stabilizes the sheath lumen 654 with respect to the pusherclasp body 296. Two pins 2962 hold the pusher clasp body 296 to theproximal handle 678 so that longitudinal movement of the proximal handle678 translates into a corresponding longitudinal movement of the pusherclasp body 296 within the handle body 674. These pins 2962 pass througha plug 2964, shown in FIG. 114 , and then into the pusher clasp body296. The length of the pins that exist through the plug 2964 and alsothrough the pusher clasp body 296 gives enough support to preventmovement of the handle 678 from breaking the pins 2962, which mightoccur if the plug 2964 were not present.

It is noted that the conical expansion of the proximal end of the innersheath 652 is different in FIGS. 97 and 98 . This is because theembodiment shown in FIGS. 97 and 98 illustrates an expansion portion ofthe inner sheath 652 that is sutured on only one side thereof.Accordingly, when viewed along the suture line (as in FIG. 98 ), thecone has one flat side. In contrast, when viewed in an elevation 90degrees turned from that suture line (as in FIG. 97 ), the expansionportion has a conical elevational view.

Also shown in FIG. 98 on the inner sheath 652 is a D-shaped radiopaquemarker 232. This marker 232 is enlarged in FIG. 99 and can be, forexample, secured to the inner sheath 652 by three sutures,diagrammatically indicated with an “X.”

FIG. 100 is an enlarged view of the distal end of the handle assembly670 shown in FIG. 90 . This embodiment of the distal apex head 636 showsan alternative embodiment of the proximal portion that was first shownin FIG. 29 . As can be seen in the drawing, the proximal side of thedistal apex head 636 is tapered. This tapered shape allows the distalapex head 636 to enter further into the interior cavity between theprongs of the proximal apex body 638 than the distal apex head 636 shownin FIG. 29 . It is noted that the portion of the delivery system at thedistal end is to be flexible so that this portion can traverse curvedvessels. Thus, it is desirable for the length of the distal apex head636 and the proximal apex body 638 (semi-rigid parts) to be as short aspossible. By allowing the distal apex head 636 to travel further intothe proximal apex body 638, the longitudinal length of the two parts 636can be shorter.

Now that the various parts of the handle assembly 670 have been shownand described separately, the interactions and orientations whenassembled can now be further understood with reference to the followingdescription and to FIGS. 101 to 105 .

FIGS. 101 to 102 show the proximal half of the handle assembly 670 fromjust proximal of the locking knob 676 to just distal of the distal endof the proximal handle 678 (when the handle 678 is in a proximalposition). The hidden lines shown in FIG. 101 aid in the understandingof this portion. It is noted that the sheath lumen 654 is notillustrated in FIG. 101 for clarity.

FIG. 102 clearly shows the components that are involved in the proximalhalf of the handle assembly 670. The handle body 674 is surrounded bythe distal handle 678 and a portion of the locking knob 676. Inside theproximal end of the handle body 674 is the clasp body 602, which issurrounded by the proximal end of the clasp sleeve 614. The lockingwasher 608 is positioned inside the clasp sleeve 614 at the distal endof the clasp body 602.

Separated at a distance from the distal end of the locking washer 608 isthe rotator assembly, which, as set forth above, is longitudinally fixedto the proximal handle 678. The rotator assembly includes the pusherclasp rotator 292 surrounding the pusher clasp spring 298 and therotator body 294. The pusher clasp body 296 is disposed on the distalend of the rotator body 294 and the crimp ring 295 secures the sheathlumen 654 on the distal projection 297 of the pusher clasp body 296.

FIG. 103 is an enlarged view of the proximal portion of FIG. 102 by thelocking knob 676. These figures show the alignment of the bores in theclasp body 602 and the locking washer 608 so that the non-illustratedsetscrew can fasten the two parts to one another. Also shown in FIG. 103is the alignment between the groove 605 for receiving therein thesetscrew 586 (see FIGS. 53 and 93 ) and connecting the proximal claspassembly 604 to the clasp sleeve 614 so that the clasp sleeve 614 canstill rotate around the clasp body 602. Also visible in the enlargedview of FIG. 103 is the three coaxial lumen 620, 640, 645 that passthrough the clasp body 602.

Like FIG. 103 , FIG. 104 is an enlarged view of the distal portion ofthe handle assembly 670 around the pusher clasp rotator 292. This viewnot only shows the orientations of the rotator body 294 and the pusherclasp body 296 with respect to the pusher clasp rotator 292, but thethree coaxial lumen passing therethrough are also evident. The groove2944 for receiving the non-illustrated dowels 2926 therein is alsovisible in this view. As can be seen, the guidewire lumen 620 and theapex release lumen 640 each pass entirely through the pusher clasp body296 but the proximal pusher support tube 645 ends just after the distalend of the rotator body 294 for homeostasis purposes. It is at this endpoint that the proximal pusher support tube 645 is connected to thegraft push lumen 642. This two-part structure of the proximal pushersupport tube 645 and the graft push lumen 642 is, in an exemplaryembodiment, a bonding of a proximal stainless steel lumen 645 and aplastic lumen 642, for example, a polyurethane-based extrusion. As setforth above, a rigid lumen 645 in the handle portion keeps rigiditythere and a flexible lumen 642 distal of the distal handle 672 allowsthe lumen to flex as needed. The distal end of the rotator body 294 isalso fluidically sealed off from the interior of the distal interior ofthe delivery system with a hemostasis o-ring 293. FIG. 105 is still afurther enlarged view around the pusher clasp spring 298.

A transverse cross-sectional view through the handle assembly 670 isillustrative of the interaction between and relationship of variouscomponents of this assembly 670. The cross-sections shown in FIGS. 106to 118 progress from proximal to distal.

A first transverse cross-section through the longitudinal slot 583 ofthe locking knob 676 is illustrated in FIG. 106 . In thiscross-sectional plane, the clasp body 602 is shown as filling up most ofthe interior of the clasp sleeve 614. The anchoring bore in the claspsleeve 614 for the setscrew 585 is shown aligned with the slot 583.

A second transverse cross-section through the three-position slot 587 ofthe locking knob 676 is illustrated in FIG. 107 . In thiscross-sectional plane, the clasp body 602 still is shown as filling upmost of the interior of the clasp sleeve 614. The slot 6022 of the claspbody 602 for receiving one end of the torsion spring 606 is alsodepicted in FIG. 107 .

A third transverse cross-section through the clasp body 602 before thelocking washer 608 is illustrated in FIG. 108 . In this cross-sectionalplane, the slot 6022 of the clasp body 602 is aligned with a slot 6143inside the proximal end of the clasp sleeve 614 that is not visible inFIG. 93 but is visible through the cutout in FIGS. 59 and 60 . Thisalignment is merely shown in FIG. 108 for understanding the differentdepths of these slots 6022, 6143. Like the pusher clasp spring 298, thedistal clasp body spring 606 has ends with different lengths. The first,shorter, end is inserted into the inner slot 6022 of the clasp body 602and the second, longer end is inserted into the slot 6143 of the claspsleeve 614.

The fourth transverse cross-section between the proximal clasp assembly604 and the rotator assembly shows, in FIG. 109 , the spatial separationof these two assemblies that is depicted, for example, in FIGS. 101 to102 . Visible in these figures is the longitudinal slot 6141 that, asshown in11 in the cross-sections of FIGS. 110 to 111 , guides themovement of the pusher clasp rotator 292 by delimiting a space thatcorresponds to the width of the boss 2924 that extends out from theouter circumferences of the pusher clasp rotator 292. This slot 6141allows the pusher clasp rotator 292 to move longitudinally freely withrespect to the clasp sleeve 614; simultaneously, this connectionprevents any rotation of the pusher clasp rotator 292 that isindependent from rotation of the clasp sleeve 614. Accordingly, as theclasp sleeve 614 rotates about its longitudinal axis, the pusher clasprotator 292 will rotate as well. The further enlarged view of the centerof the configuration illustrated in FIG. 110 is depicted in FIG. 111 .Here, the rotator assembly portions are clearly shown with the pusherclasp spring 298 therebetween.

The sixth cross-section of FIG. 112 , and the enlarged view of the sixthcross-section in FIG. 113 , illustrate the longitudinally fixed butrotationally free connection between the pusher clasp rotator 292 andthe rotator body 294. The two bores in the pusher clasp rotator 292 forreceiving the dowels 2926 (not illustrated here) are clearly shown tointersect the open space in the groove 2944 of the rotator body 294.

A seventh cross-section in FIG. 114 shows the connection of the pusherclasp body 296 and the proximal handle 678 through the plug 2964. Thisview also depicts the fluid communication between the interior of thehandle assembly 670 and the luer fitting 612. When the luer 612 isconnected to a fluid supply, the flushing liquid enters the interiorcavity distal of the rotator body 294 and sealed off by the o-ring 293and purges all air therein at the distal end of the delivery system.FIG. 114 also shows the graft push lumen 642 extending through thehandle body 674 beginning after the distal side of the o-ring 293.

The eighth cross-section of FIG. 115 illustrates the distal projection297 at which the crimp ring 295 holds the sheath lumen 654 onto thepusher clasp body 296. This figure also illustrates the open radialspace between the clasp sleeve 614 and the graft push lumen 642. To keepthe relatively long extent of the flexible inner lumen 620, 640, 642passing through the open interior of the handle body 674 from moving outof a centered orientation (i.e., from bending out from the longitudinalaxis of the handle body 674, sliding spacers 6142 are periodicallyprovided along the clasp sleeve 614 as shown in FIGS. 93 and 116 to 118. These spacers 6142 are only needed while the proximal handle 678 ismoving the rotator assembly and the pusher clasp body 296 in a distaldirection to prevent bending of the interior flexible lumen 620, 640,642. Accordingly, the spacers 6142 can slide within the groove 6141 ofthe clasp sleeve 614 up to and over the distal end of the clasp sleeve614 (the right side of the sleeve 614 as viewed in FIG. 93 ; see alsoFIG. 117 ). Each of these spacers 6142 is self secured in a slidablemanner to the clasp sleeve 614.

FIG. 117 depicts a ninth cross-section through a distal end of the claspsleeve 614 within the distal handle 672. The distal handle 672 freelyrotates about the handle body 674 in an exemplary embodiment. In such anembodiment, the outer catheter 660 will also freely rotate about all ofthe lumen 620, 640, 642 therein because of the fixation between theouter catheter 660 and the distal handle 672. See FIG. 118 .

The shaded parts in FIG. 119 are provided to show portions of thefeatures around the clasp body 602. In this view, the rotator assemblyis removed.

The following text describes the four movements for implanting aprosthesis with the delivery system and the relative connections betweenrelevant lumens when in the three different settings of the locking knob676.

The first movement will be referred to as the advancement stage andutilizes position 1 of the locking knob 676. When in position 1, thedistal spring 298 is engaged around and holds the pusher support tube645 (and, therefore, graft push lumen 642) to the rotator assembly 292,294. This assembly 292, 294 is fixed at the distal end of the rotatorbody 294 inside the pusher clasp body 296 (through a non-illustratedsetscrew passing through the threaded bore 2966 shown in FIG. 98 ). Asset forth above, the pusher clasp body 296 is fixed to the proximalhandle 678 and, therefore, the pusher support tube 245 moves with theproximal handle 678 in position 1.

In this first movement, the entire distal assembly is advanced up to theimplantation site using the proximal handle 678. Thus, when the handle678 moves distally, all of the lumen, including the guidewire lumen 620,the apex release lumen 640, the graft push lumen 642/proximal pushersupport tube 645, and the sheath lumen 654, are locked together and movedistally with a corresponding movement of the proximal handle 678. Asthe outer catheter 660 is longitudinally fixed to the distal handle 672,it remains longitudinally fixed during the first movement. The lumendisplacement in the advancement stage is depicted in FIGS. 19 to 21 .

The second movement will be referred to as the primary deployment stageand utilizes position 2 of the locking knob 676. When in position 2, thedistal spring 298 is disengaged from the pusher support tube 645 and theproximal spring 606 becomes engaged around the pusher support tube 645to anchor only the push rod 642 (without lumen 620, 640) to the proximalhandle 678 and allow retraction of sheath lumen 654 (and, thereby, theinner sheath 652) while all other lumens are disengaged and remainstationary.

In this second movement, the inner sheath 654 needs to be moved in theproximal direction, as shown in FIGS. 22 to 24 . Accordingly, when thehandle 678 moves distally, only the sheath lumen 654 moves with thehandle 678. Thus, in position 2 of the locking knob 676, the sheathlumen 654 is locked to the proximal handle 678 and moves proximally witha corresponding movement of the proximal handle 678; all of the otherlumen, including the guidewire lumen 620, the apex release lumen 640,and the graft push lumen 642/proximal pusher support tube 645, areunlocked and remain in the distally deployed position. See FIGS. 22 to24 .

The third movement will be referred to as the final deployment stagebecause, in this movement, the apex capture device 634 completelyreleases the distal end of the prosthesis as shown in FIG. 14 . Here,the apex release lumen 640 is unlocked (using the release mechanism ofFIG. 91 ) with respect to the guidewire lumen 620 and the graft pushlumen 642/645.

The fourth movement will be referred to as the extraction stage andutilizes position 4 of the locking knob (the third of the threepositions in the slot 587 of the locking knob 676). When in position 4,both the distal spring 298 and the proximal spring 606 are disengagedfrom the pusher support tube 645 to allow the user to pull the proximalend of the pusher support tube 645 and withdraw it from the implantationsite. The entire inner lumen assembly 620 and 640 travels with theproximal movement of the pusher support tube 645 because the releasemechanism (see FIG. 91 ) is pulled with the support tube 645 as it movesproximally.

Self-Centering Tip

As set forth above, the bare stent 30 provides an outward, expandingforce at the proximal end 12. The bare stent 30 and the proximal stent23 are in a compressed state when attached to the graft sleeve 10 andalso provide an outward, expanding force to the graft sleeve 10.Therefore, when implanted, these forces center the proximal end of thestent graft 1 in the vessel and press the graft sleeve 10 against thevessel wall to prevent leaks that might occur between the graft sleeve10 and the vessel wall. Such leaks at the proximal end 12 are to beavoided in stent graft implantation.

Because some physicians are concerned that the bare stent could damagethe aortic wall, especially in the case of aortic dissection, theyprefer to use a stent graft without a bare stent, such as the stentgraft 1100 shown in FIGS. 72 and 74 to 77 . In this configuration, theproximal end 12 can travel further upstream in the aorta and, in doingso, place the graft sleeve 10 closer to the heart. Such an implantationhas various advantages, such as the removal of the possibility of barestent puncture or damage to the vessel and the ability to treat diseasedportions of the aorta closer to the heart.

However, if the bare stent 30 is removed, the ability to center theproximal end 12 is affected. One deficiency of thoracic grafts nothaving a bare stent is a misalignment of the proximal end of theprosthesis with the aortic curvature, which leads to improper appositionof the proximal end of the graft with the aortic arch inner curvature.Proper apposition is a desirable characteristic.

Stent grafts, by their nature of replacing the through-conduit of adamaged tubular vessel, have a proximal opening 12 for receiving thereinthe incoming fluid previously carried by the damaged vessel. See, e.g.,FIG. 1 . It is desirable to directly contact the entire perimeter ofthis opening to the inside surface of the vessel in which the stentgraft is to be placed because an opening between the proximal end of thestent graft and the vessel wall would allow a secondary flow outside andaround the stent graft. This bypassing secondary flow is to be avoidedwhen implanting stent grafts in a vessel and is particularly undesirablewhen implanting a stent graft in the aorta. The present inventionprovides a device, system and method for reducing and/or eliminating thepossibility of such a bypassing flow by placing the proximal end 12 in adesired position within the vessel.

For the purposes of discussion, a few terms will be defined. The planeintersecting the proximal end opening of a stent graft is referred toherein as the inflow plane. The ring of tissue inside the vessel atwhich the proximal end opening is to be implanted is referred to hereinas an upstream implant ring. The plane in which the upstream implantring resides in the vessel is referred to herein as the implant plane. Alongitudinal tangent is referred to herein as a line that is orthogonalto the implant plane at a point on the upstream implant ring.

A most-desirable implantation of the stent graft occurs when the inflowplane and the implant plane are co-planar. In this orientation, thelongitudinal tangent of each point along the upstream implant plane isorthogonal to the inflow plane. This means that the outward forceimparted by the proximal end of the stent graft is along a line that isco-planar with the implant plane, thereby insuring that thefluid-sealing force of the proximal end is maximized at the upstreamimplant ring.

When a stent graft is implanted in a longitudinally straight vessel, theinflow plane and the implant plane are virtually co-planar. In thisorientation, a maximum outward sealing force is established at eachpoint on the upstream implant ring, thereby maximizing the possibilityof creating a permanent fluid-tight seal along the entire perimeter ofthe upstream implant ring.

When a stent graft is to be placed in a longitudinally curved vessel, asshown in FIGS. 19 to 24 and 65 to 67 , for example, co-planar alignmentof the implant plane and the inflow plane does not occur naturally. Infact, prior art stent grafts and delivery systems could not establishthis co-planar alignment of the implant plane and the inflow plane whenthe stent graft was placed in a curved vessel. As such, when the stentgraft was implanted in the curved vessel, the inflow plane was left atan angle to the implant plane, which, in turn, created a gap at theinferior side of the curved vessel. In some instances, this gap allowedfluid to flow impermissibly around the implanted stent graft.

One of the primary reasons for this misalignment is due to the behaviorof the guidewire within the curved portion of the vessel. The guidewire610 does not remain centered within the vessel throughout the curvedportion of the vessel—as illustrated diagrammatically in FIGS. 19 to 24and 65 to 67 . Instead, in practice, the guidewire 610 tracks toward thesuperior (outside) curve from approximately the center axis of thevessel until it actually contacts the interior of the superior curve atleast at one point within the curved vessel. The curved guidewire,therefore, not only guides the stent graft towards the superior curve,it does so while imparting an outwardly directed force to the stentgraft—a force that naturally moves the stent graft off center in thecurved vessel.

This non-axial tracking of the guidewire 610 is diagrammatically shownin FIG. 120 . Here, the inflow plane 300 and the implant plane 400 areat an angle α to one another. Because the diameter of the upstreamimplant ring 12 has a maximum length that is defined by the opening ofthe graft material, an inferior gap β appears between the inferiorcurved vessel wall and the upstream implant ring 12. The presentinvention provides devices and methods for automatically centering thestent graft 1100 within the vessel and, thereby, substantially align theimplant plane 400 with the inflow plane 300 as shown in FIG. 121 . Asused herein, substantial alignment of the implant plane 400 and theinflow plane 300 is an angular difference of less than 15 degreesbetween the two planes.

A first exemplary embodiment of the device that improves proximal endapposition when it is placed in the aortic lumen prior to deployment incurved anatomy is illustrated in FIGS. 122 and 123 . The previouslydescribed tip 632 is altered as shown in FIG. 122 . The new tip 632′ hasan overall length that is greater as compared to the tip 632. The distalsection 6322′ is tapered similarly to tip 632. The proximal section6324′ is straight and, hence, not bendable while tracking over theguidewire 610. This stiff proximal section 6324′, along with the stiffdistal and proximal clasps, produces an elongated stiff region in thenose cone assembly 630 of the delivery system 600. This stiff regiondoes not accommodate the superior curvature of the aorta and pushes thedistal end of the delivery system down towards the inferior curvaturewhen tracking in curved anatomies.

FIG. 123 illustrates how a modified tip pushes the proximal end of thestent graft down (as viewed in FIG. 123 ) towards the inferior curve ofthe curved aortic lumen. If the proximal end 12 of the stent graft 1100is deployed while centered as shown, the proximal end 12 will haveproper apposition with the aortic wall at the inferior curvature.

A second exemplary embodiment of the proximal end apposition improvementdevice is illustrated in FIGS. 124 to 126 . In this embodiment, the tip632″ contains therein a set of balloons 6322″ that, when inflatedindependently, exit and extend from a respective slit 6324″. The numberof balloons can be 1, 2, 3, 4, or more. In the exemplary embodimentsshown, there are three balloons spaced 120 degrees apart from oneanother. Which balloon(s) that are inflated after the tip 632″ ispositioned in the curved vessel will depend upon the position of theslits 6324″. As shown in FIG. 125 , one balloon 6322″ can be inflated tocenter the tip 632″ or, as shown in FIG. 126 , all three balloons 6322″can be inflated.

A third exemplary embodiment of the proximal end apposition improvementdevice takes its genesis from the bare stent 30. In all of theembodiments for improving apposition, the bare stent 30 is removed.Because some physicians are concerned that a bare stent can damage anaortic wall, especially in the case of aortic dissection, the inventionproposes creating a bio-absorbable bare stent. Such a bare stent 30dissolves over time but ensures proper alignment of the proximal end ofthe graft during deployment. Because the bare stent is absorbed, anypotential for damaging the aortic wall is eliminated.

A fourth exemplary embodiment of the proximal end apposition improvementdevice is illustrated in FIGS. 127 and 128 . A dual-cone 410 devicecenters the nose cone assembly 630 of the delivery system 600 within thelumen. Centering the nose cone assembly within the aortic lumen, inturn, will ensure that the proximal end of the stent graft 1100 isproperly aligned with the aorta. The dual-cone device can be made ofsilicone. The bases of the two opposing conical parts are adjacent oneanother. When the ends of the conical parts are pressed towards oneanother, the diameter of the conical base increases. As the baseincreases in diameter, its circular expansion comes in contact with thesuperior curve of the aortic wall to force the nose cone assembly 630towards the center of the aortic lumen. When fully expanded, theproximal end 13 of the stent graft 1100 is in a desired centeredposition and is, therefore, ready for deployment. It is noted that theshape of the conical components can be modified to allow greaterexpansion of the conical base at specific locations.

A fifth exemplary embodiment of the proximal end apposition improvementdevice is illustrated in FIGS. 129 and 130 . This centering system usesa pull-wire 420 that can center the tip end of the delivery systemwithin the aortic lumen. The pull-wire 420 resides inside the deliverysystem between the stent graft 1100 and inner sheath 652. One end of thepull-wire 420 can be attached to the nose cone assembly 630, forexample, the proximal apex body 638 and the other end of the continuouswire is attached to a mechanism at the proximal portion of the deliverysystem 600, whether at the proximal end of the handle assembly 670 or atthe apex release assembly 690. This mechanism, when operated, pulls thewire proximally to produce a force P having two resultant forces P′ andP″ shown in FIG. 130 . even though P′ is the smaller of the tworesultant forces, if force P is large enough, P′ will pull the tiptowards the inferior curve of the aorta. FIG. 129 illustrates the distalend of the delivery system being centered by pulling on the wire 520 tocreate centered apposition of the proximal end 12 of the stent graft1100.

A sixth exemplary embodiment of the proximal end apposition improvementdevice is illustrated in FIGS. 131 and 132 . The apex clasp device 636,638 is formed in two halves or three thirds. In this configuration, thesplit clasp mechanism allows angular adjustment of the proximal end ofthe graft within the aortic lumen to insure optimum apposition with theaortic wall as shown in the comparison of FIGS. 131 and 132 . The splitclasp allows the user to move forward and backward some specific apicesalong the proximal circumference of the stent graft 1100 which, in turn,changes the angle of the inflow plane 300 with respect to the implantplane 400. By using this process and system, the physician can adjustthe orientation of the proximal end 12 to ensure proper appositionagainst the aortic arch inner curvature.

A seventh exemplary embodiment of the proximal end appositionimprovement device is illustrated in FIGS. 133 to 135 . As set forthabove, the apex clasp device 636, 638 uses a set of distally projectingfork tines and an internal castellated portion to create openings inwhich the proximal apices 32 of the bare stent 30 or the proximal apices1132 of the clasping stent 1130 are held releasably. Instead of the apexclasp device 636, 638, each of the apices 32, 1132 are individually heldwith an apex capture mechanism that is shown in FIGS. 133 to 135 .Pushing the wire in one of the apex capture mechanisms causes theproximal end 12 of the stent graft 1100 to move. A combination of suchpushing forces on one or more of these apex capture mechanisms willcause the proximal end 12 to move into a desired apposition of theinflow plane 300 and the implant plane 400. When the wires are pulled,they move proximally and release the capture of the respective stentapex 32, 1132.

An eighth exemplary embodiment of the proximal end appositionimprovement device is illustrated in FIGS. 136 to 142 . Here, the tip632 has slots through which extend loops of wires that, when extended asshown in FIGS. 137, 141, and 142 , center the tip 632 within the vesselin which it is placed. The mechanism is composed of wires that arecontained inside the slots in a straight configuration. Compressing thewires causes them to protrude from the slots and form loops that canpress against the vessel wall, thereby centering the tip 632 within thevessel. Extension of the loops can be actuated through a single pullmechanism, for example, with a telescoping slide. Centering of the tipis actuated by pulling on a knob (for example) located at the proximalend of the delivery system. The knob is connected to the wire loops by acatheter that extends from the knob to the distal end of the loops. Theloops, in turn, are fixed at their distal end. Pulling on the knob wouldcause the catheter to slide in a proximal direction causing acompression of the wire loops, making them protrude from the tip 632 asshown in FIGS. 137, 141, and 142 . In addition, the catheter can containa component that engages the clasp as it is moved proximally. Thus, asthe catheter is moved, at approximately three-fourths of the actuationstroke, the component on the catheter engages the clasp and with theremainder of knob retraction the clasp would be released.

A ninth exemplary embodiment of the proximal end apposition improvementdevice is illustrated in FIG. 143 . In this approach, an accessorydevice 430 is introduced into one or more of the contra lateral limbs ofthe patient or radially through the arm. Before, during or after, thedelivery system is used to extend the aortic stent graft into the aorticarch for implantation. The accessory device 430 is, then, extended intothe aortic arch and pressed against a portion of the delivery system.For example, as shown in FIG. 3 , the accessory device 430 can beintroduced through the left sub-clavian artery and used to bias thedelivery catheter away from the greater curve of the arch. The accessorydevice 430 can have many forms. It could be a balloon, a mechanicalmechanism, and a pusher from the trans-femoral approach, a balloon or amechanical mechanism is practical. Each of these concepts can be appliedin a direct approach from the left sub-clavian artery or theBrachiocephalic Trunk.

A tenth exemplary embodiment of the proximal end apposition improvementdevice is illustrated in FIGS. 144 to 146 . In this embodiment, theproperties of temperature sensitive nickel-titanium are combined withthe technology of localized heating to present a controlled shapemanipulation. Shape memory bends are imparted to portions of thedelivery system 600 prior to incorporation in the delivery system 600.Then, the portions are placed into the desired configuration, e.g.,linear, and incorporated into the delivery system 600. Heater bands 440are distributed along the delivery system 600 adjacent the memory bends.As shown in FIGS. 144 to 146 , application of heat at the memory bendswill cause the adjacent portion of the delivery system 600 to bend. Ifthe bends are coordinated, they can be made to bend the in-vivo deliverysystem 600 in any desired way, in particular, to center the tip in thevessel and, thereby, implant the proximal end 12 of the stent graft 1100with a proper apposition. Alternatively, ultrasonic sensitive crystalscan be used as the heater bands. Thus, when energy is applied, thecrystal heat up and cause the nickel-titanium memory portion to bendinto their pre-programmed memory shape.

An eleventh exemplary embodiment of the proximal end appositionimprovement device is illustrated in FIGS. 147 to 151 . In thisembodiment, a hollow balloon delivery catheter 450 having a balloonconfiguration 452 is provided. The balloon delivery catheter 450 has aninterior bore 454 through which the outer catheter 660, the nose coneassembly 630, and the inner sheath 652 travel. FIGS. 149 to 151illustrate an exemplary method for using the balloon delivery catheter450 of the present invention. First, the balloon delivery catheter 450is inserted into at least part of the aortic arch and the balloonconfiguration 452 is inflated to center and hold the balloon deliverycatheter 450 in position within the aorta. See FIG. 147 . Then, thedistal end of the delivery assembly 600 is passed through the balloondelivery catheter 450 as shown in FIG. 148 . The proximal end 12 of thestent graft 1100 is deployed in the aortic arch and, after satisfactoryapposition of the inflow plane 300 and the implant plane 400 isverified, the balloon configuration 452 is deflated and the balloondelivery catheter 450 can be removed. Finally, the stent graft 1100 isfully implanted as set forth above.

In the exemplary balloon configuration 652 shown in FIGS. 150 and 151 ,there are three balloons 452 with spaces therebetween so that blood canflow past the balloons 452 when inflated. This tri-balloon device isshown in FIGS. 150 and 151 .

Alternative to the balloon delivery catheter 450, a balloonconfiguration 452 can be added at the distal end of the outer catheter660. When the outer catheter 660 is at its distal-most position in theaorta, the balloon configuration 450 inflates and centers the nose coneassembly 630 within the aorta. Thus, when the inner sheath 652containing the stent graft 1100 is extended from the outer catheter 660,the nose cone assembly 630 is centered within the aorta and the innersheath 652 and nose cone assembly 630 can be extended within the aorticarch in a centered orientation.

A twelfth exemplary embodiment of the proximal end appositionimprovement device is illustrated in FIGS. 152 to 155 . In thisembodiment, a balloon delivery rod 460 having a balloon configuration462 is provided. The balloon delivery rod 460 is inserted into at leastpart of the aortic arch and the balloon configuration 462 is inflated atthe superior curve of the aortic arch. See FIG. 152 . Then, the distalend of the delivery assembly 600 is passed through the aorta and alongthe inflated balloon configuration 462 as shown in FIG. 153 . Theproximal end 12 of the stent graft 1100 is deployed in the aortic archand, after satisfactory apposition of the inflow plane 300 and theimplant plane 400 is verified, the balloon configuration 462 is deflatedand the balloon delivery rod 460 can be removed. Finally, the stentgraft 1100 is fully implanted as set forth above. FIG. 155 illustratesone possible cross-sectional configuration for the balloon 462 of thisembodiment.

A thirteenth exemplary embodiment of the proximal end appositionimprovement device is illustrated in FIGS. 156 to 158 . As describedabove, a proximal edge 12 that is perpendicular to the longitudinaledges (see FIG. 71 ) will be difficult to position in a curved vesseland, in such a case, the inflow plane 300 will be at an angle to theimplant plane 400 as shown in FIG. 157 . To counteract thisnon-apposition of the proximal end 12 that does not have a bare stent,the stent graft 1100 can be formed with a non-linear proximal end 12′ asshown in FIG. 158 . With this angled contour, if the shorter side (leftside in FIG. 158 ) is positioned at the inferior curved of the vessel,the proximal end 12 will fit inside the aorta to align the inflow plane300 and the implant plane 400 as shown in FIG. 158 .

A fourteenth exemplary embodiment of the proximal end appositionimprovement device is illustrated in FIG. 159 . The tip 632 or the nosecone assembly 630 is configured with a symmetric dilator 470 shown inFIG. 159 . This dilator 470, when closed, is merely a cylinder. However,when opened as shown in the figure, the two outer bearing surfaces 472apply pressure to opposing sides of the vessel in which the stent graft1100 is to be implanted, thereby centering the nose cone assembly 630and the proximal end 12 within the vessel for implantation withapposition of the inflow plane 300 and the implant plane 400.

A fifteenth exemplary embodiment of the proximal end appositionimprovement device is illustrated in FIGS. 160 and 161 . In thisembodiment, a plurality (e.g., four) of wires 480 are threaded throughthe delivery assembly 600 and are attached to, for example, fourquadrants of the apex capture device 634. At the proximal end of thedelivery assembly 600 is located an actuation knob or “joystick” 482. Bypulling or otherwise maneuvering the knob 482, tension is applied to oneor more of the wires 480 and moves the tip 632. Such maneuvering is usedto center the tip 632 as desired to ensure apposition of the inflowplane 300 and the implant plane 400.

A sixteenth exemplary embodiment of the proximal end appositionimprovement device is illustrated in FIGS. 162 and 163 . Because bloodis flowing through an aorta in which a stent graft 1100 is to beimplanted, properties of the flow can be used for making perpendicularthe stent graft's proximal opening with the tangent of the aortic archto provide an optimal proximal seal. In particular, a tapered “windsock”490 can be incorporated into the delivery assembly 600. The proximaldiameter of the windsock 490 is large enough so that, upon expansion dueto the incoming blood flow, the proximal opening 492 of the windsock 490opens and presses against the aortic wall. In such a configuration, thewindsock 490 channels all blood flow therethrough and discharges theflow from a distal opening 494. The distal opening 494 is made to besmaller than the proximal opening 492. The change in opening sizeincreases the pressure in the wind sock 490. When the blood flow ischanneled into a path that is concentric within the aorta, such asthrough an evenly spaced set of exit orifices 494, the balanced (andcentered) pressure would radially center the leading portion of thestent graft 1100 during deployment.

In one exemplary configuration shown in FIG. 162 , the proximal end 492of the windsock 490 is attached with sutures to the apex capture device632. The distal end 492 of the windsock 490 may or may not be attachedto a portion of the delivery assembly 600 distal of the proximal end 12of the stent graft 1100 to be deployed. Compare FIGS. 162 and 163 . Itis noted that having no distal attachment (FIG. 163 ) may be moreadvantageous because performance of blood flow balancing may be betterthan with distal attachment (FIG. 162 ). If the distal end 494 of thewindsock 490 is attached, a break-away method for the sutures can beused along with the incorporation of blood flow ports as illustrated inFIG. 162 . Performance of the windsock 490 can be evaluated with varyingdischarge port diameters and overall tapers.

A seventeenth exemplary embodiment of the proximal end appositionimprovement device is illustrated in FIGS. 164 to 169 . In thisembodiment, a plurality of memory shape metal (e.g., Nitinol) hypo-tubes500 are attached to the delivery assembly 600 and act as a mechanism tocenter the tip and, therefore, the stent graft 1100 during stent graftpositioning and deployment. In one exemplary embodiment, two controltubes or lumens 502, 504 are placed somewhere between, around, or overthe apex release lumens 620, 640. Each of the hypo-tubes 500 is securedat its distal end 506 to the inner control tube 502 at or near the tip632. Each of the hypo-tubes 500 is further secured at its proximal end508 to the outer control tube 504 at a distance from the tip 632. Asillustrated in the comparison of FIGS. 165 and 166 , forward(advancement) motion of the outer control tube makes the hypo-tubes 500expand into a “basket” shape that contacts the walls of the aorta andcenters the proximal end 12 of the stent graft 1100 within the vessel.When in this advanced position of the outer control tube 504, as shownin FIG. 164 , the hypo-tubes 500 are used to create an arc duringpositioning and, thereby, facilitate the centering function. Backwards(retraction) motion of the outer control tube 504 decreases the profileof the hypo-tubes 500 to lie longitudinally along the length of theinner control tube 502.

To incorporate this feature into the stent grasping device that connectswith each of the proximal apices 1132 of the clasping stent 1130, eachhypo-tube 500 has a small “notch” 510 (slightly larger than the diameterof the wire of the clasping stent 1130. This “notch” is located at thecenter of the pre-formed arc of the hypo-tubes 500 (see FIGS. 166, 167). Inside the diameter of the hollow hypo-tube 500 is a rigid releasewire that acts to engage the proximal apices 1132 to attach releasablythe clasping stent 1130 to the delivery system. See, e.g., FIGS. 133 to135 . The releasable clasping shown in FIGS. 168 and 169 ensures asecure lock of the stent graft 1100 to the delivery assembly 600. Duringattachment of the stent graft 1100 to the delivery assembly 600, theapices 1132 of the clasping stent 1130 are positioned into each notch510 and the rigid release wire is fed over the clasping stent 1130 tocapture (secure) the clasping stent 1130 and secure it to the deliveryassembly 600 (see FIG. 169 ). Release of the stent graft 1100 from thedelivery assembly 600 is obtained by withdrawing the rigid wire withinthe hypo-tubes 500. Expansion of the pre-formed nitinol hypo-tube 500can be performed manually (slide action) or through a self-expandingconfiguration.

An eighteenth exemplary embodiment of the proximal end appositionimprovement device is illustrated in FIGS. 170 to 172 . In thisembodiment, the tip 632′″ has been given expandable exterior segments6322′, in this case, three segments. The tip 632′″ also contains aninterior expansion mechanism, for example, a spring actuated or pusheractuated mechanism, that extends the exterior segments 6322′ from theposition shown in FIGS. 170 and 171 to the position shown in FIG. 172 .When the tip 632′″ is so expanded, it becomes centered within the curvedvessel, thereby also centering the proximal end 12 of the stent graft1100.

The tip-centering embodiments are not limited to the distal end of thedelivery assembly 600. The guidewire 610 can also be utilized. Morespecifically, in a nineteenth exemplary embodiment of the proximal endapposition improvement device, the guidewire 610 can be provided with anexpanding “basket” 520 at the distal end thereof as shown in FIGS. 173to 175 . This basket 520 can be either self-expanding or manuallyexpanded and opens within the aorta when the basket 520 is just upstreamof the implant plane 400. The delivery assembly 600 is, then, introducedover the guidewire 610 to the deployment site. After delivery of thestent graft 1100, the guidewire 610 is withdrawn into the guidewirelumen 620 of the delivery assembly 600 and withdrawn along with theassembly 600.

A twentieth exemplary embodiment of the proximal end appositionimprovement device is illustrated in FIG. 176 . This embodiment providesan alternative to the bio-absorbable bare stent 30 by including aremovable bare stent 30′. Utilizing such a bare stent 30′ duringdeployment but removing it after apposition of the inflow plane 300 andthe implant plane 400 is confirmed provides the self-centering featuresof the original bare stent 30 but without the detrimental affects thatcan be caused by the long-term exposure of the bare stent 30 to theinterior wall of the vessel in which the stent graft 1100 is implanted.This removable bare stent 30′ can be fixed onto or be a part of the apexcapture device 634. The bare stent 30′ can be fixedly secured to theproximal end of the distal apex head 636, for example, and removablysecured to the proximal end 12 of the stent graft 1100. Detachment ofthe bare stent 30′ can be accomplished in a variety of ways. Oneexemplary embodiment can collapse the bare stent 30′ with a collectionring that slides over the bare stent 30′ in a proximal direction. As thering progresses proximally along the individual turns of the bare stent30′, a radially inward force is imparted to each proximal apex 32′sufficient to release or break the contact between the apex 32′ and thestent graft 1100. Another exemplary bare stent removal device reversesthe orientation of a hook that connects each apex 32′ to the stent graft1100 so that the apex capture device 634 is moved distally to releasethe bare stent 30′ from the stent graft 1100.

It is envisioned that any of the nineteen exemplary embodimentsdescribed above can be used individually or in any combination.

While exemplary embodiments of the invention have been illustrated anddescribed, it will be clear that the invention is not so limited.Numerous modifications, changes, variations, substitutions, andequivalents will occur to those skilled in the art without departingfrom the spirit and scope of the present invention as defined by theappended claims.

What is claimed is:
 1. A centering system for an aortic stent graftprosthesis, comprising: a) guidewire catheter (620) having a proximalend and a distal end; b) a nose cone (630) fixed to the distal end ofthe guidewire catheter (620); c) an apex capture device (634) at thenose cone (630); d) a stent graft prosthesis (1, 1100) having a proximalend 02) and a distal end (14), and a clasping stent (1130) defining bareapices (1132) at the proximal end of the stent graft prosthesis (1,1100), wherein, during delivery to a treatment site, the apices (1132)are releasably captured by the apex capture device (634); e) an innersheath (652) extending about the stent graft prosthesis (1, 1100); f) aplurality of wires (480), each independently fixed to the apex capturedevice (634) and collectively distributed radially about the guidewirecatheter (620), wherein the plurality of wires (480) extend distallybetween the stent graft prosthesis (1, 1100) and the inner sheath (652),whereby relative longitudinal movement of the wires (480) along theguidewire catheter (620) causes a change in orientation of the apexcapture device (634) at the proximal end of the stent graft prosthesis(1, 1100) to thereby center the proximal end of the stent graftprosthesis (1, 1100) within an aorta at a treatment site; and g) atapered windsock (490) outside of the stent graft prosthesis (1, 1100),the tapered windsock (490) having a proximal open end (492) and a distalend (494) that is smaller than the proximal open end (492), the proximalopen end being attached to the apex capture device (634) by sutures,wherein the distal end (494) of the tapered windsock (490) is attachedto a portion of the remainder of the centering system distal to theproximal end (12) of the stent graft (1, 1100), and wherein the distalend (494) of the tapered windsock (490) defines openings.